Isaac

Isaac (ロビン Robin) is a Venus Adept who is one of the main protagonists in Golden Sun and Golden Sun: The Lost Age. As the leader of a group of friends consisting of Garet, Ivan, and Mia throughout both entries of the series' GBA duology, Isaac is the main character in the first game and one of the most significant characters in the overall. The player directly controls Isaac throughout all of Golden Sun, and late in The Lost Age, Isaac's group joins the ranks of a second group led by his temporary antagonist Felix to form that game's final party. In Golden Sun: Dark Dawn, Isaac is a significant NPC who sends his son Matthew on a very different kind of quest across a much-changed world. Isaac is often seen as the most central representative of his series and the closest to being its main character overall; this is reflected in his prominence in Golden Sun-related material that makes cameo appearances in the Super Smash Bros. series.

Isaac starts the series as a young resident of the village of Vale who makes the difficult decision to embark on a quest across the world of Weyard to safeguard it from a presumed doomsday that would be brought about by the release of the ancient and sealed power of Alchemy. Though he is tasked by the godlike entity known as the Wise One to use his powers as an Adept to negate the efforts of a band of intruders led by Saturos and involving Felix to prevent the activation of the Elemental Lighthouses that will herald Alchemy's return, Isaac's perspective eventually changes upon learning of the necessary significance of Alchemy to the world itself.

Within the thirty years that elapse after he brings about Alchemy's revival with the other seven heroes known in retrospect as the Warriors of Vale, he becomes a controversial figure who is both praised and blamed for bringing about a power that is as destructive to the world's populace as it is necessary. After becoming the husband of fellow Vale resident Jenna and fathering their son Matthew, Isaac eventually sends Matthew and several of the Warriors' other children on a quest intended to hone their skills as Adepts looking out for the world's welfare while continuing his own investigation into a dangerous natural phenomenon that has since come about as a side-effect of Alchemy's return.

As a playable character
Isaac is featured in Golden Sun as one of the four party members used throughout the game to conduct all of the game's battles with spiritual powers called Psynergy. He is the resident Venus Adept of the four Adepts, thus granting him the ability to use a variety of Earth-aligned Psynergy in his default Squire class series; alternatively, he can be customized to use a blend of Venus Psynergy and Psynergy of other elements by changing his class series accordingly via Setting different elements of Djinn onto himself.

More specifically, Isaac is formally the leader of the party in the first game, which results in him being the character that the player directly controls as an avatar throughout the entire game's out-of-battle segments and overworld. His party members are considered to be perpetually accompanying him even though he is the only one visible in the game's setting, and the rest only appear either in battles or in cutscenes. As per series tradition, while Isaac can initiate conversations with all manner of other NPCs, he is never depicted as speaking with anyone in the first game because he is restricted to the parameters of the "silent protagonist" archetype. As later games show, however, this seemingly mute depiction does not accurately reflect his speaking habits.

Isaac, like the other Venus Adepts who lead their own parties in their respective games -- Felix in The Lost Age and Matthew in Dark Dawn -- always has access to the near-exclusive Retreat Psynergy, which gives players the highly important quality-of-life function of transporting the party back to the entrance of a given dungeon-like area. He also innately knows the Move Psynergy like the aforementioned party leaders and certain other characters, which is a very commonly used tool for solving environmental puzzles.

Isaac starts the first game as a younger form of himself in a stormy prologue sequence in Vale as an extremely weak and unnamed class without any access to any Psynergy. When the story shifts to the present day, he debuts as his stronger version with access to the Squire class series (a series exclusive to himself and Felix that indicates that they are "warrior-style Adepts" of the Venus element); he starts at Level 1 like Garet and Jenna, who are also present in his party, and his initial equipment includes a Short Sword, a Cotton Shirt, and Padded Gloves. As the first game progresses, Isaac usually establishes himself as a superior combatant over the more defensively inclined warrior-style Mars Adept Garet.

Roughly three quarters of Golden Sun: The Lost Age takes place with the player controlling an entirely separate party led by Felix, and Isaac and his own party are unavailable until a point late in the game that is internally referred to as the "Reunion." Once this transpires, Isaac, Garet, Ivan, and Mia are added as party members who can be switched into and out of the overall party's four active combatant slots both outside battle and during it. By default, Isaac and his other three party members will all join at Level 28, each with five out of seven of the original game's 28 Djinn. Isaac will personally be equipped with generic starting equipment that includes a Great Sword, a Knight's Shield, a Knight's Helm, and a Steel Armor, and he will also be carrying all of the original game's unavoidable Utility Psynergy items -- Catch Beads, Douse Drop, Frost Jewel, Lifting Gem, and Carry Stone.

However, a special Password function exclusive to The Lost Age can be used to dictate the overall power and development of Isaac and his party by the time they join Felix's. Through using either a Game Link Cable and two separate Game Boy Advance systems or a generated text password that has to be manually entered, Isaac and his party can be made to join Felix's party with the exact levels, EXP, inventory, wealth, and Djinn collection as they had at the end of the player's playthrough of the first game. This is the only way to make sure that Isaac and his friends come with a complete collection of Djinn and the rather important Orb of Force Utility Psynergy item (as well as the no-longer-useful Cloak Ball and Halt Gem).

Classes and Statistics
Before the statistical modifications of character classes are taken into account, Isaac would have the second highest Attack rating of the eight party members used throughout the GBA games. His Agility is also moderately high, and his HP is above average. The only other character to have an innate Luck rating of 3 is Piers. However, his PP is below average. Isaac is extremely similar to Felix both in terms of default class series and statistical inclinations; he naturally features significantly more Agility, slightly more PP, and an extra point of Luck, but Felix offers a higher HP rating and slightly more Attack and Defense. Either Venus Adept can be made into the most destructive in Golden Sun: The Lost Age by far because both are capable of equipping the weapon that offers the most powerful Unleash effect in the game, the Sol Blade.

Isaac, just like Felix, has access to the following class series based on how many of what elements of Djinn he keeps Set onto himself (with series listed as "Partial" being series Isaac cannot advance to the highest class stages of):


 * Mono-Elemental: [[File:Star_venus.gif]] Squire
 * Dual-Elemental: [[File:Star_venus.gif]][[File:Star_mars.gif]] Brute, [[File:Star_venus.gif]][[File:Star_jupiter.gif]] Apprentice, [[File:Star_venus.gif]][[File:Star_mercury.gif]] Swordsman (Venus)
 * (Partial) [[File:Star_jupiter.gif]] Seer (Jupiter), [[File:Star_mercury.gif]] Seer (Mercury)
 * Tri-Elemental: [[File:Star_venus.gif]][[File:Star_mercury.gif]][[File:Star_mars.gif]] Dragoon, [[File:Star_venus.gif]][[File:Star_jupiter.gif]][[File:Star_mars.gif]] Ninja, [[File:Star_venus.gif]][[File:Star_mars.gif]][[File:Star_jupiter.gif]] Samurai
 * (Partial) [[File:Star_venus.gif]][[File:Star_mercury.gif]][[File:Star_jupiter.gif]] Medium

In Golden Sun: Dark Dawn
The adult version of Isaac is featured early in Golden Sun: Dark Dawn as a computer-controlled "guest" character that temporarily joins the party of Matthew and Karis with the adult version Garet during the Tanglewood segment of the game's opening chapter. He will remain as an uncontrolled fixture in the party up through the Tangle Bloom boss encounter in the Abandoned Mine; his stats will not be viewable, but his in-battle model confirms that he is equipped with a Great Sword. During this "tutorial" segment of the game, Isaac and Garet are effectively indestructible and can annihilate monsters in one attack. Isaac is given to Unleashing the Venus Djinni Flint for massive damage if the player has already unleashed two of their own Venus Djinn, which allows the player to quickly summon Cybele (or possibly Judgment). Isaac will also immediately unleash the Venus Djinni Salt if any member of the party is afflicted with any status condition, and he will similarly unleash the Venus Djinni Quartz to attempt to partially revive Matthew or Karis if either of them are Downed.

Appearance and Personality
Isaac's most recognizable physical qualities are messy dirt-blond hair and blue eyes. As his younger self, he wears a blue outfit adorned seemingly with gold plating and wears leather gloves and boots, but the most recognizable extension of his wardrobe is a yellow scarf. His relatively thin build for a male his age develops as he ages roughly ten years physically over a thirty-year stretch of time (this being an outcome of a plot-related occurrence during his story). As a roughly fifty-year-old adult physically in his early thirties, Isaac has allowed a short beard to grow and now wears a blue trench-coat.

Isaac has a relatively calm demeanor from the start, which is consistent with other earth-elemental Adepts seen throughout the series. Like them, he is seen as bearing leadership qualities, which naturally incline others in the group of Adepts he assembles to defer to his judgment. He maintains trust in a childhood friend even after she apparently throws her lot in with an enemy of Isaac's who was complicit in letting her be taken hostage, but when that enemy later saves Isaac's life despite continuing the aims Isaac seeks to defeat, Isaac shows a willingness to trust his enemy's judgment and motivations.

Isaac was raised in an environment that ascribes to faith in a perceived deity-like being (this religious overtone is more overt in the Japanese version of Golden Sun); when said entity reveals itself to Isaac and portrays the goal of a dangerous band of rogues as seeking to unleash a dangerously abusable power across the world, Isaac thus accepts the staggering responsibility of leaving his home village and worried mother behind to pursue his designated enemies abroad. At a much later point in what turns out to be a quest filled with troubling developments, however, he learns startling truths about the nature of the quest handed down to him and the goals of his opponents, which makes him ask a former enemy why they had not approached him before. However, he is humbled when it is suggested in hindsight that he would not have broken away from his perceived responsibilities at that earlier point in time because it would have meant violating his home's sacred teachings. Isaac eventually shows himself capable of defying the very entity his culture had deified to serve more immediately important needs for his world, and at unimaginable personal expense on top of that.

While pursuing a dangerous quest as he had initially understood its implications to be, Isaac shows a willingness to briefly diverge from his set path to help those who his enemies have deliberately caused problems for — even when doing so runs counter to the fact his quest is one where time is of the essence. Nevertheless, he is also capable of a level of pragmatism as a leader, as seen when he deals with a monarch based near one of his objectives who is currently relying on the rather questionable means of keeping a foreign girl captive in his palace to coerce her home village into helping him with what is ultimately a self-serving goal. Because it would be more difficult for Isaac to protect his next objective from his own enemies otherwise, he agrees to serve the monarch's aims in the future through use of a special ship (this agreement also results in the girl being allowed to return to her village). Later, when Isaac has a need to use this ship to pursue his opponents across the world's oceans, he considers additionally seeking the objective of said monarch to be a matter of honorably upholding a promise he made.

As an adult, he considers a lot of the responsibility for the years of chaos that falls upon Weyard as an outcome of his quest to fall on him personally. Now given to praying desperately toward the open air for answers from the deity-like being that revealed itself to be dispensing a point when it put Isaac's group through the great ordeal they faced years earlier, he trains his son Matthew in the field of becoming a warrior like he was. He is single-minded in his belief that the children of his world-known faction must become accomplished Adepts to inherit their parents' responsibility to Weyard, and he sends Matthew, Karis, and Tyrell on a difficult quest across the continent to give them the opportunity to learn discipline when Tyrell impetuously breaks something important. In a mirror to how his own mother was too distraught to see him off from his own quest, Isaac stays behind at his cabin when Matthew sets out on his own quest.

Isaac is also shown as an adult to value being seen as always having the right answer. At times, when he comes up with a hypothesis about an issue, he prefers to withhold a direct explanation and instead lead others along with specific instructions so that they will accomplish his intended outcome and prove his point for him in advance. Isaac sees this as a more efficient method of keeping others interested in his latest idea. Similarly, when he sends Matthew and Tyrell on a quest, he withholds a strict order for Karis to accompany them so as to allow her voluntary willingness to do so to be drawn out first.

History
Isaac was born and raised in Vale, a village situated at the base of the dormant volcano Mt. Aleph in western Angara, and he lived the first fourteen years of his life with his parents Kyle and Dora and his friends Garet, Jenna, and Felix. Like his parents, Isaac is a Venus Adept; all of Vale's people are Adepts to varying degrees because the village has for a long time been persistently exposed to the effects of a giant Psynergy Stone formation within its perimeter. Isaac was well-liked by the villagers and seen as highly reliable and caring, and his mother described him as being a great deal like his father was at his age, including his stubbornness. Having lived within the bounds of Vale's relatively sequestered society and customs his entire life, Isaac had yet to leave the village or become aware of the existence of "the ocean" even as he entered his late teens. When the elderly scholar of Alchemy Kraden moved to the village, Isaac would visit Kraden's cottage on many occasions.

In Golden Sun
The story of the first Golden Sun is told through Isaac's perspective, so Isaac is depicted as a silent protagonist whose thoughts and statements are implied and open for the player to interpret.

The Mt. Aleph Boulder incident
When he was fourteen years of age, however, Isaac was among many in Vale whose lives were forever altered by a tragic incident brought upon Vale by Mt. Aleph itself. The Mt. Aleph Boulder, a giant boulder located somewhere on the mountain, became dislodged as a result of a freak nighttime thunderstorm and rolled directly through Vale, and Jenna's house was completely destroyed; Isaac, Dora, Garet, and Jenna could only watch as the boulder seemingly killed Kyle, Felix, and Felix and Jenna's parents directly in front of them. In a daze, Isaac wandered off through the rest of the village on his own, and Garet followed him. The two boys soon crossed paths with a duo of menacing and mysterious strangers, Saturos and Menardi, who were heard remarking that their failed efforts to intrude upon Mt. Aleph's Sol Sanctum were responsible for the mountain conjuring the storm. The two exceedingly powerful Mars Adepts promptly rendered them unconscious with their Mars Psynergy and left Vale under the cover of darkness. Both boys would lose their memories of this encounter.

The Mt. Aleph Boulder disaster led to an emotionally trying period of time for Isaac and his mother, but their grief was obviously eclipsed by that of Jenna; her entire family was perceived to have been gone forever, though neither their bodies nor Kyle's were ever discovered along the river the boulder fell into. Isaac personally felt that things would have been different had he possessed the Psynergy powers necessary to save the victims, so he and Garet resolved to train in the ways of Adepts and attain the power to protect and defend. Kraden willingly assisted them in their studies.

Infiltrating Sol Sanctum
Three years after the Mt. Aleph Boulder disaster, Isaac — now seventeen — has become a strong, reliable young man who, along with Garet and Jenna, has developed his aptitude with Psynergy powers. One day, Kraden convinces the three young Adepts to join him in a secret investigation of Sol Sanctum, presenting this as a necessary part of their studies — even though the elders of Vale do not normally permit entry into the sanctum that Vale's populace collectively regards as their traditional duty to safeguard. Entirely by coincidence, however, Saturos and Menardi return to Vale the day this expedition is set to be undertaken, and Isaac and his friends overhear the in-their-minds-unfamiliar strangers discussing how to use Kraden in their newly planned attempt to infiltrate Sol Sanctum again. The two groups cross paths and briefly engage in a tense interaction before Isaac is allowed to go to Kraden without incident. Kraden discusses with the young Adepts how the two strangers had apparently been at Sol Sanctum before and may be planning on robbing it, and he decides to use this to further justify the immediate commencement of their own investigation, claiming that they can find out firsthand whether the duo are to be outed and punished as thieves.

Kraden and Isaac's group sneak into Sol Sanctum and explore its hallowed confines, but even after they find the evidence they need against the two strangers, Kraden lets his curiosity overtake his better judgement and has the group forge into the last, sealed chamber. The four are humbled as they behold the all-powerful Elemental Stars set into their respective pedestals, and on Kraden's urging, Isaac and Garet set off to remove and retrieve the Elemental Stars for him to study.

After collecting the Mercury, Venus, and Jupiter Stars, however, Isaac and Garet watch in alarm as Saturos and Menardi invade the chamber, take Jenna and Kraden hostage, and demand that Isaac and Garet hand over all four of the Elemental Stars in exchange for the hostages' freedom. Isaac and Garet are given a compelling reason to submit when the Mars Adepts reveal that they have brought along two companions, one of whom — to everyone's disbelief — is a very-much-alive Felix; he reveals himself to have sworn himself to Saturos' cause because his life was saved by Saturos three years earlier. After handing their three Stars to Saturos' other newfound partner in crime, a powerful Mercury Adept named Alex, Isaac and Garet move to retrieve the remaining Star, the Mars Star, for them.

The moment the Mars Star is removed from its pedestal, the entire chamber quakes as Mt. Aleph suddenly begins to erupt, and Isaac and Garet watch in amazement as the Wise One, the all-powerful entity long deified by the healers of Vale, emerges into view. Saturos' group rationally decides they cannot afford to stay in the chamber and must leave Isaac and the Mars Star behind to flee Mt. Aleph; however, they decide to keep Jenna and Kraden in their custody because it would increase the likelihood that Isaac will survive the eruption and seek Jenna's freedom, perhaps bringing the Mars Star with him.

The Wise One directly addresses Isaac and Garet and reveals that Saturos' group means to use the four Elemental Stars to light the beacons of four massive, ancient edifices located across Weyard known as the Elemental Lighthouses. Doing so will restore the power of Alchemy to the world — but the Wise One warns that this must be stopped because it can be a dangerous power for the world at large if misused. After imbuing the Mars Star in Isaac's possession with an as-of-yet unexplained effect, the Wise One teleports Isaac and Garet to safety and redirects the flow of lava away from Vale.

Isaac and Garet are quickly ushered by Vale's concerned residents into Vale's Sanctum so that they can explain everything that happened. During the urgent town meeting, Vale's Great Healer relays the Wise One's telepathic message that Weyard's fate depends on whether Isaac and Garet will take up the responsibility to stop Saturos and Felix before Alchemy can threaten the world's peoples with its unchecked power. This exceedingly weighty decision is left to Isaac and Garet individually, but Garet quickly leaves his share of the decision to Isaac. Isaac ultimately accepts the burden of safeguarding the world from a potential era of destructive chaos.

Neither the Wise One nor Vale's healers have much to share with Isaac and Garet in the way of guidance or instructions, but the mayor and the rest of the villagers agree to let Isaac and Garet spend one last night with their families before the two set off on their dangerous mission the following day. When the next day arrives, however, Isaac is not personally seen off by his own mother because she is too distraught to bear doing so, so Garet's younger brother bestows Isaac Dora's Catch Beads on her behalf. After the entire village sees Isaac off with a hearty farewell, Isaac commences his urgent adventure across Angara in the hope that he can both prevent Saturos and Felix from activating any of the Elemental Lighthouses and rescue Jenna and Kraden from their captivity.

Mercury Lighthouse
Isaac and Garet head toward the closest town, Vault, to gain their bearings and work out Saturos' likeliest initial destination. Their aptitude as warriors and Psynergy wielders are quickly tested and refined as they battle countless wild monsters now roaming the lands in a decidedly more agitated state; this change in the world's sense of stability has been brought about because the eruption of Mt. Aleph showered the entire world with Psynergy Stones that are both causing random people across the land to acquire new powers as Adepts and driving the minds of lesser creatures mad. The eruption also scattered countless elemental spirits named Djinn across the world; as Isaac and Garet befriend Djinn such as Flint, they find that their combat prowess, Psynergy potency, and even access to elements of Psynergy other than their own are bolstered all the more drastically.

At Vault, Isaac and Garet encounter the wayward Jupiter Adept Ivan and help him regain an important artifact, the Shaman's Rod. After Ivan uses his Psynergy-based ability to read minds to learn everything that happened to Isaac and Garet and how it relates to the unsettling changes sweeping across the world, he decides to permanently accompany Isaac on his quest in a bid to stop worse things from happening.

The early stages of Isaac's quest soon direct him to Angara's snow-covered northern stretches, wherein lies Mercury Lighthouse. A female Mercury Adept and healer from the nearby town of Imil, Mia, is sworn to the charge passed down by her ancient Mercury Clan that Mercury Lighthouse remains safeguarded from intruders — so when Mercury Lighthouse evidently gets intruded, she hastily joins Isaac in climbing up through the ancient tower's passageways to investigate the pinnacle of the structure. To their shared distress, they discover that the Mercury Star has already been cast into the gaping well at the aerie of Mercury Lighthouse, permanently establishing the Mercury Beacon.

The culprits are revealed to still be present; Menardi and Felix and their captives Jenna and Kraden call out to Isaac's group from the opposite end of the aerie before Saturos has them head to the next Lighthouse. Saturos complements Isaac and Garet's survival up to this point and promises that they will not be alive for much longer — but he is shocked to discover that his own Mars-aligned powers are severely inhibited by the Mercury-aligned influence now being exuded by Mercury Lighthouse. Even so, Saturos proves to be a very fearsome and powerful opponent for Isaac's Adepts indeed, but Mia's bolstered abilities help Isaac miraculously turn the tables and render Saturos prone on the ground.

Alex then makes himself known after having secretly watched the Adepts from afar and compliments Isaac on how quickly his group has become accomplished warriors. Mia harshly rebukes Alex, her own cousin, because he betrayed the oath of their shared bloodline and has instead activated Mercury Lighthouse out of an evident desire to let a great power run unchecked. After confirming that Isaac still has the Mars Star with him, Alex helps Saturos up and leaves Mercury Lighthouse with him. Disheartened that she has failed her clan and her duty, Mia willingly accompanies Isaac on the remainder of his quest to stop Saturos and Alex's group from activating any more Lighthouses.

Quest across two continents
Isaac leads his three companions Garet, Ivan, and Mia clockwise across Angara in pursuit of Saturos' group of Adepts and unwilling captives, all the while entering unfamiliar settlements, helping locals whose livelihoods have been thrown off course either directly by Saturos' group or indirectly through Mt. Aleph's eruption, and exploring caves and other environments whose obstacles and resident monsters obstruct Isaac's course. By the time the company makes it to Ivan's hometown of Kalay in southwestern Angara, Isaac and Garet are afforded an opportunity to revisit Vale back to the north and temporarily reunite with their respective families; though Dora is greatly appreciative of Isaac's visit, she has by now grown ill with a cold brought upon herself by her consistent fear for her son's safety. Knowing now that Saturos crossed the Karagol Sea to the continent southwest of Angara, Gondowan — wherein lies Venus Lighthouse — Isaac's group takes a none-too-pleasant voyage on a ferry service across the enclosed sea to follow him.

Isaac's party touches down on Tolbi, the most populated settlement in the world, which is currently holding a festival centered around its world-famous annual tournament of warriors, Colosso. Isaac gets a hold of the news that Tolbi's mysterious ruler, Lord Babi, is missing, and he follows a lead into the nearby Altmiller Cave and soon discovers Babi on the verge of death. Isaac saves his life by bringing him the fluid Babi was seeking in the cave, Lemurian Draught — which Babi had stockpiled within the cave a long time ago. Babi takes a keen interest in Isaac and his friends for the particular powers they exhibit, and he decides to personally register Isaac as a Colosso Gladiator for the upcoming Colosso Finals so that he may observe Isaac's abilities to their fullest extent. Isaac participates without a say in the matter, and his performance in the tournament is deemed to be brilliant.

Babi reveals that he was seeking warriors with Psynergy powers because he needs such a group to discover the ancient and hidden island city of Lemuria far out in the Great Eastern Sea so that more draught can be retrieved to extend his life — for Babi is 150 years old and just about out of his personal stockpile. He had once found himself within Lemuria's borders, and he eventually departed the isle on a Lemurian Ship and had taken a massive stockpile of the draught with him. In his efforts to continue extending his life beyond his normal years (efforts that originally saw to him sending Kraden to Vale to study Sol Sanctum), Babi had been coercing a town near Gondowan's Venus Lighthouse, Lalivero, to help build a lighthouse in Babi's name so that ships entering the misty Sea of Time containing Lemuria can keep a straight course. Meanwhile, only the Lemurian Ship can reasonably be expected to complete the expedition, and only Adepts can control the ship.

Despite Babi's offer for generous rewards if his group takes up this quest, Isaac and his friends seem neutral regarding helping Babi achieve his particular ends (even though they do not know at this time that Babi had actually stolen the draught and the ship described) — but they ultimately swear the oath because it would be more difficult for Isaac to enter Venus Lighthouse and stop Saturos otherwise. At the same time, through completing his own quest, Isaac would help Babi indirectly because clearing the way through Venus Lighthouse so that Babi's men can reach its aerie would fulfill the original intent of Babi Lighthouse's construction. Babi has his chief minister, Iodem, accompany Isaac on the journey toward Venus Lighthouse.

Venus Lighthouse
As Isaac and Iodem's group journey to Lalivero, however, they discover that Saturos has taken a young Laliveran girl named Sheba as yet another captive; Sheba was originally held by Babi in his palace to secure Lalivero's cooperation in constructing Babi Lighthouse but had been allowed to return to her people once Babi found Isaac's group to be more directly useful to his plans. Uncertain as to why Sheba would be taken as well, Isaac leaves Iodem behind as his group of Adepts enters Venus Lighthouse and uses their developed repertoire of powers to solve the structure's ancient riddles and reach the tower's aerie as fast as possible, intending both to prevent the Venus Beacon from being lit and to relieve Saturos of his three hostages.

Isaac and his friends reach Venus Lighthouse's aerie just in time to witness friction fermenting between Felix and Saturos over the latter's decision to involve Sheba in their struggles. Isaac's group initiates a tense standoff with Saturos and Felix, during which Saturos reveals that Sheba is actually a Jupiter Adept — and as such is vitally necessary for Saturos' side to be able to enter Jupiter Lighthouse in the future. Saturos also reveals, to Isaac's surprise, that the Shaman's Rod is also necessary for Jupiter Lighthouse in some way. Saturos then promises that he will not harm Sheba if Isaac gives Felix the Shaman's Rod — and through crafty wording, Saturos tricks Isaac's side into interpreting this as a promise that Sheba will be allowed to go free, perhaps letting Isaac perceive an implication that the rod is at least more directly necessary for the long-term success of Saturos' plans than access to a Jupiter Adept at the moment. After they hand the rod over, the Adepts are exasperated when Saturos issues his subsequent clarification about his terms, and he and Menardi decide it is time for Isaac's party to die.

The Mars Adepts launch an all-out offensive against Isaac's party. However, because of the degree to which Isaac and his companions have become powerful as Adepts by this point, they manage to defeat both of their experienced foes. Isaac's side is taken aback, however, when Felix then combatively insists that the Lighthouse beacons must still be lit, confirming that his willing participation in Saturos' goals was never dictated by him being bound to Saturos' will in any way; Isaac is forced to conclude that Felix is their enemy. The Adepts' disbelieving attitudes suddenly transform into shock and horror when Saturos and Menardi, out of nowhere, casually toss the Venus Star into the Venus Lighthouse's well, instantaneously failing another step in Isaac's quest.

As Venus Lighthouse trembles, the energy it lets loose restores Saturos and Menardi's Psynergy reserves and empowers them, and the duo make their last stand against Isaac's stunned party by merging and transforming into a massive two-headed dragon. Through an incredibly intense and harrowing battle, Isaac and his friends ultimately slay the beast, and Saturos and Menardi revert back to their defeated forms before limply falling into Venus Lighthouse's well and meeting their shared demise.

Witnessing Isaac's incredible victory, an intimidated Felix declares that he is no longer a match for Isaac and that he must flee with Sheba to continue Saturos' quest to light the remaining beacons; however, he refuses to elaborate on what he fears will happen if the quest is not finished. Isaac's side is about to consider taking Sheba from Felix by force when, suddenly, Venus Lighthouse wracks itself with a violent earthquake as it forms the Venus Beacon — and Isaac and his companions watch in shocked disbelief as Sheba loses her footing and falls off the towering structure and Felix deliriously jumps clean off the tower after her. After the chaos subsides, Isaac and his companions somberly leave Venus Lighthouse anticipating that they need to find Jenna and Kraden and break the news to them that Felix and Sheba are both dead.

Isaac and his friends proceed to conduct a long and tiring search for Jenna and Kraden in the vicinity of Venus Lighthouse and Lalivero, but they are never found. Astonishing accounts from the people of Lalivero reveal to Isaac, however, that both Sheba and Felix likely survived their fall because the ocean coincidentally rose up to catch them at just the right moment — an occurrence the Laliverans attribute to Sheba's mysterious knack for having coincidence play out in her favor. Since the earthquake that shook Venus Lighthouse tore off a peninsula from Gondowan named Idejima and resulted in it floating out into the ocean, Isaac is left to assume that Felix and Alex may well be continuing Saturos' quest with Jenna, Sheba, Kraden, and the Shaman's Rod in tow.

Since they need a sea vessel to search the open seas of Weyard for their enemies, Isaac's party promises Iodem that they will use their time spent sailing on Babi's Lemurian Ship to additionally seek Lemuria and retrieve Lemurian draught before Babi's time forever runs out. With the Black Orb that controls the Lemurian Ship granted to them by Iodem, Isaac's group sets sail in pursuit of multiple objectives.

In Golden Sun: The Lost Age
In contrast to the previous Golden Sun, the story of Golden Sun: The Lost Age is told through Felix's perspective, so Isaac and his group are not encountered in person for much of the game. During his own quest, Felix can learn what Isaac has been up to recently by talking with townsfolk at certain points in the game.

The Great Eastern Sea
Over an indeterminate period of time, Isaac and his party of Adepts explore the Great Eastern Sea in search of any available information regarding Felix, his captives, and the Sea of Time enclosed within the middle of the ocean. Isaac labors under a strong belief that the world would be in terrible danger should he fail to prevent either of the two remaining Lighthouses from being lit; however, for the time being, the only route between continents that would have given him access to the Great Western Sea and the remaining two lighthouses is blocked off by natural obstacles. Given the wide scale of the Eastern Sea, Isaac can only hope to encounter Felix somewhere within the world by pure chance.

Isaac may or may not end up making a serious attempt within this time frame to sail Babi's ship through the craggy stretches of water surrounding the Sea of Time within which Lemuria lays hidden. Granting that Isaac does, even though Venus Lighthouse's active beacon would provide enough of a powerful source of light that it would give Isaac enough of a point of reference that he can keep his bearings, Isaac's group would ultimately fail because the treacherous maze of whirlpools and stone crags that make up the sea's perimeter can only be passed with special knowledge of how certain strong currents can be negated by sailing in specific patterns. Even if Isaac's group discovered such knowledge, they nonetheless would have inevitably been turned back by a monstrous sea god named Poseidon prowling the grounds; this entity is completely invulnerable to all forms of assault Isaac and his friends would have access to.

During Isaac's time frantically sailing the Eastern Sea, he and his friends land at Apojii Islands and behold Gaia Falls, the collective term for the waterfalls adorning Weyard's perimeter that endlessly fall into the void above which Weyard is situated. If the Sun Saga, the popularized retrospective on Isaac's journey that would be in print as of thirty years later, is to be taken at face value, then Isaac's travels abroad would see to him coming across hearsay that paints Felix in an unexpectedly heroic light at several instances. For example, Isaac would hear of Felix putting the notorious pirate Briggs in his place and slaying the Great Serpent that was terrorizing the island village of Izumo.

At any rate, Isaac at some point touches down on Indra and learns from the villagers at Madra that a man named Piers, who they recently released from captivity, has both Mercury-aligned Psynergy powers and a Lemurian Ship just like theirs. Shocked by this revelation, Isaac declares that he will follow Piers toward where he was last seen headed — the heart of lower Gondowan — because he sees Piers as the last chance his group has at fulfilling the contractual vow his group made to Babi. Before leaving, however, Isaac and his friends decide to show the Madrans examples of some of their own Psynergy powers to explain what Piers had previously demonstrated; for Isaac and Garet to do this is rather interesting because it technically breaches a law and code of Vale that those who leave the village on business must never show Psynergy to outsiders.

Isaac and his friends proceed into lower Gondowan and stop in its southernmost village, Naribwe, and Isaac pays the local innkeepers a large sum of coins to get them to agree to pass the message onto Piers — should they see him — that Isaac wants to meet him. They also resort to engaging the local Fortune Teller thoroughly for his predictive services. If Isaac makes an attempt to follow Piers to Kibombo, however, it can be guessed that he is ultimately turned back by the Kibombo warriors stationed at the Kibombo Mountains. Isaac and his group ultimately never come across Piers — or Felix's group for that matter — at any point during their time Great Eastern Sea.

It is uncertain whether Isaac's party catches wind of the subsequent news within this time frame that Babi has finally passed away, though granting this it can be speculated that this development weighs heavily on Isaac because it amounts to him having once again failed to achieve a significant objective he agreed to. At any rate, Isaac and his friends eventually make the decision to head west toward Jupiter Lighthouse.

Jupiter Lighthouse
The oceanic passage into the Great Western Sea has had its natural obstacles cleared away by this time, so Isaac and his companions sail directly toward Atteka, the continent on which the next lighthouse they must protect from Felix, Jupiter Lighthouse, is situated. They briefly stop in the settlement of Contigo on their way to the lighthouse.

While Isaac's party scales Jupiter Lighthouse, however, they are suddenly divided by a trap that separates Garet and Mia from the others, and Isaac and Ivan are immediately approached by a new duo of Mars Adepts, Karst and Agatio. Isaac, evidently strained from prior events as is, immediately and brusquely tells them to leave him be so that he can save his friends on his own, but Karst and Agatio gleefully confirm their involvement in the trap. Isaac correctly determines that they hail from the same clan as Saturos and Menardi; indeed, they have come down south all the way from the declining village of Prox to exact revenge upon Isaac for his murder of their clansmen (and family, in the case of Karst). Isaac and Ivan desperately engage Karst and Agatio in a two-on-two battle but are overpowered in the end.

Just as the duo of Mars Adepts are about to finish the wounded Isaac off, all of a sudden, Felix steps in to stop them, backed up by the party he has been traveling Weyard with up through this point — consisting of Jenna, Sheba, Piers, and Kraden. Karst and Agatio are puzzled by Felix's intent to keep Isaac alive, given that the two groups had previously crossed paths and Felix reaffirmed to Karst at the time that he would light Jupiter Lighthouse as she wished, but Felix flexes his side's superior manpower and state of health to force Karst and Agatio into accepting a deal where Isaac's party will be allowed to live if Felix takes the Mars Star from Isaac and then goes to light the Jupiter Beacon. As Isaac lies on the ground, he sees the actions of his once-childhood friend Felix for what they are and decides to trust Felix's judgment despite how much they have been at odds with each other up until now, and so he willfully hands Felix the Mars Star. Isaac and his party are tended to by Jenna, Sheba, and Kraden as Felix and Piers follow Karst and Agatio up to the aerie of Jupiter Lighthouse.

After Isaac's party is nursed back to health, Jenna and Sheba suspect something may be wrong because Felix has yet to return, so they head up to the aerie to check up on Felix. Once Isaac's party fully recuperates, they head up to the aerie of Jupiter Lighthouse to discover that Felix's party had just concluded a violent skirmish with Karst and Agatio, who have just fled the lighthouse with the stolen Mars Star in their possession. With the Jupiter Beacon now alight, Isaac demands that Felix explain himself on all counts, but everyone is quick to agree that this currently is neither the best place nor time to hold a lengthy discussion. After Felix agrees to the proposal that they meet in Contigo and Jenna asks for Isaac's trust, Isaac affirms that he had never stopped trusting her but nonetheless sternly warns Felix not to sneak away again. Isaac and his party depart for Contigo ahead of Felix.

The Reunion
Isaac and his companions wait in an empty house in Contigo until Felix and his party arrive, prompting Isaac to commend Felix for keeping his word. On why Felix had been avoiding Isaac up until now, Felix's side puts forth the explanation both that they had wanted to prevent a fight — particularly for Jenna's sake — and that Felix could not bear to face Isaac for betraying Vale and then getting Jenna and Kraden caught up in his aims. As for why Felix was so dead set on helping Saturos and Menardi, Isaac learns the incredible revelation that the Mt. Aleph Boulder disaster had killed none of its presumed victims. Saturos had saved the lives of Isaac's father and Felix and Jenna's parents that night, but he brought them north to Prox and had his village keep them as prisoners so as to coerce Felix into lighting the Lighthouses at all costs. Felix had intended to win his parents' freedom, and Jenna willfully joined her brother's cause once she learned of the truth.

Though striving to fulfill Saturos' quest to light the Elemental Lighthouses was originally pursued by Felix for personal reasons, Felix's side of the discussion proceeds to share an even more stunning revelation to Isaac, one that they had discovered over the course of their quest: Weyard itself has been gradually deteriorating ever since Alchemy was sealed by the ancients ages ago, with Gaia Falls slowly but steadily consuming more of the world's perimeter every day. The absence of free-flowing elemental energy has been responsible for stunting the growth of civilization to the point that modern society is but a shadow of its former self, and Weyard will assuredly collapse and suffer a much more dire fate unless all four of the Elemental Beacons are lit in time.

Isaac is greatly taken aback because he had long labored under the impression that releasing Alchemy's volatile influence upon the world would trigger the world's destruction on different terms. Isaac asks Felix why the latter had waited so long to tell him, reasoning that he would have helped Felix, but Kraden puts Isaac on the spot by suggesting that Isaac would not have violated the sacred teachings of Vale so readily. Since the world's current course will assuredly doom it, however, Isaac finds it in himself to agree to join Felix in risking great damage in the name of ensuring the world's long-term future. Upon learning from an oracle that Karst and Agatio mean to use the Mars Star to light Mars Lighthouse north of Prox but will be decisively stopped and defeated by a powerful force, Isaac and Felix's disparate parties join forces and resolve to journey north, recover the Mars Star, and finish the job.

Mars Lighthouse
For the remainder of Felix's journey, Isaac's group shares Felix and Piers' Lemurian Ship and apparently leaves behind the ship originally lent to him by Babi. As the world steadily grows colder on account of the Elemental Lighthouse of Fire being now the only one that has yet to spread its influence, Felix and Isaac's combined party of Adepts crosses into the bleak, winter-ridden landscape of the Northern Reaches and reaches Prox, the hometown of Saturos, Menardi, Karst, and Agatio and the village wherein the parents have remained as Prox's nominal captives.

Isaac finds firsthand that the people of Prox were the first to discover that the edge of the world was steadily eroding and are now at the most immediate risk of becoming the first victims of Weyard's slow death. Prox's messengers had attempted to convince Vale's elders of the plight the world faces, but they were forcibly driven away. Responding to their people's desperation, the Elder of Prox and the chieftain Puelle had dispatched their foremost warriors, Saturos and Menardi, to covertly raid Sol Sanctum for the Elemental Stars and use them to light the four Beacons.

When Prox is made aware that it was Isaac who killed Saturos and Menardi, Isaac jumps and momentarily assumes a defensive posture in front of their countrymen, but Kraden tells him off and puts into perspective for Prox's people how Isaac ultimately cannot be blamed for having set out to pursue the warriors who stole from his home's sanctum and endangered Vale by setting off a volcanic eruption. The court of Prox's opinion finds that Isaac should take pride in having proven himself stronger than the Mars Adepts ultimately were, and Puelle trusts that Isaac and Felix's group will recover the Mars Star from Karst and Agatio's failed effort to light Mars Lighthouse and successfully use it to save Prox and all of Weyard. However, while Puelle had previously ordered the release of Kyle and the parents of Jenna and Felix upon Felix's return to Prox, Isaac and Felix's party discovers that they mysteriously headed into Mars Lighthouse before the Adepts arrived.

While Isaac and Felix's combined party scales Mars Lighthouse, they encounter and dispatch a pair of lumbering dragons — but the dragons suddenly transform back into the defeated forms of none other than Karst and Agatio. Nearing death, the Mars Adepts share their account that an entity they confusedly refer to as "the eye" peered into their souls and unilaterally decided that they lacked the conviction to go any further before changing their forms and blacking out their minds. Possibly remaining unaware of Isaac's presence, Karst and Agatio attribute their discovery by Felix to a stroke of luck and entrust the Mars Star to Felix's party so that he may finish their work. Felix and Isaac's party make their way to the aerie of Mars Lighthouse as Karst and Agatio are left behind to struggle to stay alive long enough to witness the emergence of the Mars Beacon.

At the pinnacle of Mars Lighthouse, Isaac and Felix's party are shocked to find the Wise One himself waiting to rebuke them. The Wise One demands to know why Isaac has disobeyed his command to recover the Elemental Stars and is now trying to break Alchemy's seal, and Isaac joins everyone else in explaining what they found out about the creeping doom facing Weyard on account of it. Isaac, in particular, mounts a retort against the Wise One's suggestion that Prox must "pay the price" for the "sin" of enacting the effort to light the Lighthouse Beacons.

Despite calls for the Wise One to stop protecting the Lighthouses at the world's expense, the Wise One counters with the scenario that mankind, given the realities of human nature, may very well destroy Weyard themselves if allowed access to a destructive power such as Alchemy — and reveals a particularly stunning truth that reinforces his case that the Adepts cannot hope to fully ensure that Alchemy will never be used for evil. The Adepts are staggered when they learn that Alex is currently at the peak of Mt. Aleph awaiting the lighting of the final beacon so that, when Alchemy is returned to the world via an explosive effect at Mt. Aleph introduced as "the Golden Sun," he will be at the center of the process and gain supreme power for himself. Isaac nonetheless rationalizes that the world as a whole cannot afford Alchemy's continued absence in the long term and urges Felix to throw the Mars Star into the beacon's well.

Despite the Wise One's stated decree that he cannot interfere in the actions of mankind, the godlike being prevents Felix from using the Mars Star and declares that the Adepts will only be able to ignite the Mars Beacon if they can "defeat a miracle" — which is revealed to be a colossal three-headed dragon that he summons. As the Adepts steel themselves for their final battle, Isaac is the only one who makes the connection as to what the Doom Dragon truly is: his own father and the parents of Felix and Jenna, having been transformed and forced to fight their unwitting children. But Isaac willfully keeps silent and joins his companions in slaying the beast because he accepts that he must sacrifice what is dearest to his heart in a situation that exclusively pits the survival of the world's peoples against that.

At the conclusion of the tumultuous battle, Isaac remains stoic even as his peers express horror, grief, and rage over the revelation of who exactly they have killed. Isaac soon broadcasts how he had known from the very beginning what he was about to do and declares that their parents would understand their decision to defy the Wise One in order to save the entire world. The other Adepts generally find it within themselves to agree with Isaac on this point. With their quest almost at its somber conclusion, Isaac remains with his dying father as Felix casts the Mars Star into the Mars Lighthouse's well.

Epilogue
With the Mars Beacon now fully formed, the four Elemental Lighthouses begin reacting in unison and bathe their respective aeries in elemental energy as they fire beams into the airspace above Mt. Aleph. In the Golden Sun event that follows, a great, luminous sphere of energy is formed and explodes, restoring Alchemy to the world. Isaac and his companions are unable to leave the aerie in time to avoid the Mars Beacon's particular expulsion of energy, but in what they may perceive as a miraculous circumstance, both their bodies and the bodies of their dying parents absorb a great deal of raw power — decisively preventing the parents from dying. Isaac and Felix's party transports the three parents away from Mars Lighthouse and back to Prox, and the people of Prox help nurse the parents back to health.

At a later point in time, Isaac, Felix, and Kraden are personally thanked by the Elder of Prox and Puelle for saving their town and bringing about a new golden age for the world's civilizations. As the Adepts and their revived parents begin the voyage back home to Vale, however, they fear for the safety of Vale and its citizens because of their proximity to the explosive Golden Sun event; Isaac is especially concerned for his mother because she was ill in bed the last time he saw her.

Isaac asks Kraden why the Wise One forced the Adepts to fight and kill their own parents when it seems in retrospect that the Wise One would have known in advance that the energy of the Mars Beacon would have revived them anyway. Kraden's only guess is that the Wise One's ultimate intention in all this was to test Isaac and his friends' resolve and willingness to put aside their personal concerns in the name of the world's greater good. Whether or not society makes use of Alchemy's power to rise above petty feuds may depend on the active involvement of Adepts who have risen above that level to serve greater ideals.

When Isaac and Felix's group finally returns to Vale, they make the personally shattering discovery that Vale has been wiped clean off the map by the destructive energy of the Golden Sun. For a short period of time, Isaac and Kyle absorb the apparent death of Dora in stunned sorrow while Garet grieves for his entire family... But then, they are suddenly greeted by Dora and everyone else believed to have perished, revealing that they are alive and well because the Wise One telepathically warned all of Vale's residents to evacuate the village in time. Isaac and Kyle embrace Dora as a family for the first time in years as everyone else celebrates the survival of the townspeople.

The next thirty years
Isaac and his companions proceed to make the assumptive conclusion that Alex, the one who made use of them all to gain ultimate power for himself, had died from the explosive events that took place at Mt. Aleph when he attempted to take the power of the Golden Sun for himself. They remain unaware that he had gained greatly bolstered Psynergy power and life expectancy but had otherwise failed to get the full extent of what he sought. This outcome was ensured by the Wise One since the moment he first emerged in Sol Sanctum's Elemental Star Chamber, when he apparently discerned Alex's long-term plans and imbued the Mars Star in Isaac's possession with a countermeasure that would ensure that part of the Mars Star's forming power would go to Isaac instead of Alex. At any rate, Alex is never seen by any of Isaac's companions and contacts throughout the thirty years to follow.

In the years immediately following the conclusion of Isaac and Felix's shared quest, the aftereffects of the explosive Golden Sun event renew Weyard's life force as a whole, but at stunningly great expense to its peoples; all manner of earthquakes, tsunamis, and tornadoes reshape the landscape and torment those who had until beforehand been unaware of Weyard's original slide toward oblivion. Needless to say, Isaac and his companions, who would be recognized across global society and collectively referred to as the "Warriors of Vale," are seen by the world's denizens in an extremely controversial light; many praise their efforts and many others blame them for causing such great destruction. As Isaac himself would later describe it, the new status quo for Weyard and its societies sees to its nations being driven to fight each other like animals acting out of desperation.

One particularly dire manifestation of the damage Isaac is viewed in some circles to have wrought upon Weyard is believed to be a lingering aftereffect of the Golden Sun event: Psynergy Vortexes, which are distortions in space that suck the elemental energy out of the world and from Adepts in their vicinity. One particularly immense Psynergy Vortex makes an appearance ten years after the Golden Sun event, and a vortex of the same scale emerges ten years following that; at least one of these super-sized vortexes transpires in the center of Angara, where it causes such unimaginable destruction and misery that the apparently consistent phenomenon of such a vortex emerging once every ten years is collectively referred to in society as the Mourning Moon.

In the years following the Golden Sun event, a large fraction of the surviving townsfolk of Vale resettle at various points across the newly upheaved Goma Plateau nearby, and the Warriors of Vale themselves split up and either return to their hometowns, resettle in nations such as Kalay, or wander abroad. Isaac and Garet take it upon themselves to remain in the Goma region and carefully monitor and study the Psynergy Vortexes and other aftereffects of the Golden Sun event. Understandably, Isaac holds himself responsible for ushering in Weyard's chaotic state of affairs and considers it his duty to find answers for its peoples; nevertheless, he is often given to calling out to the sky in prayer in hopes that the Wise One, who he perceives to watch over Weyard, will either have mercy on the world or give its peoples guidance on what must be done next to save the world from chaos.

Several among the Warriors of Vale bear offspring over the course of the thirty-year time frame, and Isaac becomes Jenna's husband and has a son with her, Matthew; it can be presumed that Matthew is conceived roughly thirteen years after the Golden Sun event. The Warriors seemingly share the mindset that their children must be trained as Adepts so that they can collectively bear the torch and watch over the world in their parents' stead. Isaac and Garet raise their sons Matthew and Tyrell at the cabin that Isaac gets built on Goma Plateau so that he can closely observe Mt. Aleph from afar using a telescope.

Believing that the best chance for answers to the chaos plaguing Weyard lies in the ruins of Sol Sanctum within Mt. Aleph, Isaac arranges for Ivan to develop a radical new tool that can allow him to better carry out his vigil: a Psynergy-controlled harness with wings Ivan calls a soarwing, which can be used to fly over the uncrossable terrain surrounding Mt. Aleph as needed. At the time this concept is agreed on, Isaac is apparently aware of a mammoth species of bird that roosts on the peaks at Angara's northeastern edge. Deified by the locals as the Mountain Roc, the bird's feathers are deemed to be the most critical material in the soarwing's construction. Whether it takes place before or after Matthew's birth, Isaac and several others, including Kraden, make a trip across Angara; this journey is uniquely challenging because the continent and its terrain have been radically reshaped by the Golden Sun.

Among the Golden Sun event's many surprising changes to the world has been the rise of a new race of hybrid beastmen, who claimed Angara's northeastern territorial expanse as their place in the world and named it the Morgal region. The remnants of ancient ruins were chosen as the base for the new society's capital city, Belinsk. Isaac, Kraden, and others from the Warriors of Vale arrive at the city and receive an audience with the beastman king because he views their famed images as peerless warriors to be worthy of merit. This is apparently true to such an extent that the king willingly assists the Warriors in their efforts to retrieve a feather from the Mountain Roc at Talon Peak despite how negatively that would go over with the masses, who view the creature as a national symbol. With the feather in hand, Isaac and his companions make the journey home — incidentally avoiding a subsequent imperial takeover of Morgal by the nation on its southeast border, Sana.

As of thirty years after the Golden Sun event, it has become apparent to all of the Warriors of Vale that their rates of aging have been abnormally slow; Kraden, seemingly the most dramatic example of this phenomenon because he is now over a century old and yet is still exploring Weyard, theorizes that the energy everyone absorbed at the aerie of Mars Lighthouse is the cause. This trait apparently has not passed down to their children. Isaac is obviously more concerned with the likelihood that the Mourning Moon will once again make an appearance — and soon, since it has been roughly ten years since the last incident. On top of all this, for reasons that currently remain unknown, Isaac now believes that an individual who apparently bears an absolute hatred of the Wise One is targeting the entity, and Isaac views stopping this person at any cost to be his duty.

In Golden Sun: Dark Dawn
It apparently takes Ivan over ten years to design and produce his soarwing invention, but he eventually has his daughter Karis travel to Lookout Cabin to deliver it to Isaac and Garet. Just as Isaac and his son Matthew — who is now sixteen — return from a trip to the nearby supply outpost run by Patcher, however, they come across a commotion on the rooftop being aggravated by Tyrell, who has impulsively taken the soarwing for himself with the intent to briefly fly around with it. Karis' retorts and Isaac and Garet's stern warnings that Tyrell does not yet have the training to manage it compels Tyrell to defiantly go anyway, citing dissatisfaction with how little people take him seriously. When Tyrell realizes too late that he is indeed falling toward the forest below, Isaac instructs him to fly to a small peak that contains an abandoned Psynergy Stone mine so that the adults can fetch him.

Isaac then tells Garet that they must take Matthew and Karis along to retrieve Tyrell with them because the children will need field experience as the next generation of Adepts to look after the world. Garet mounts an objection at first because the two adults would be better equipped to pass through the treacherous Tanglewood forest quickly on their own, but Isaac convinces him that Tyrell is resourceful enough at fending for himself that they can afford the extra time bringing Tyrell's friends along.

Garet defers to Isaac's judgement that they scout the cave at Goma Plateau while Matthew and Karis are suiting up and deliberately set up a natural obstacle to force their children to rely on Psynergy to pass it. Even so, Garet remains worried for his son and initially pushes back against Isaac's suggestion that they follow Matthew and Karis at a distance so that the young Adepts can learn firsthand how to handle themselves against wild monsters. Isaac's attunement to the earth allows him to verify that Tyrell is safe in the mines far away, and thus he gets to have his way for a while as the four Adepts proceed in the direction of the mine. When night falls and the Tanglewood becomes all the more dangerous for it, however, Isaac concedes the need to stick closer to Matthew and fight alongside him when necessary, and the adults lend their children several of their personally favored Djinn — including his lifelong friend Flint — to empower them. Isaac's attunement to earth and plants also allows him at one point to work out a method of clearing away roots obstructing their path by shooting fireballs at sensitive points.

When the four Adepts reach and investigate the abandoned Psynergy Stone mine, however, they are startled to find a rather large Psynergy Vortex pulsating inside — and Tyrell lying unconscious near it because he got close enough to have had all of his Psynergy drained from his body. When they approach, they are attacked by an enormous and monstrous plant growing near the vortex, and the adults help their children dispatch the unexpected threat. To allow Tyrell to regain consciousness and recover, Isaac and Garet transfer some of their Psynergy reserves into his body. While everyone is glad Tyrell is alive, the soarwing is revealed to have been destroyed from Tyrell's landing, and Isaac tells Tyrell that he will need to go on a trip to get a replacement Mountain Roc feather for the repairs.

Back at Isaac's cabin the following day, Isaac decrees that Matthew accompany Tyrell on the latter's quest to retrieve the Mountain Roc's feather from the distant Morgal region because Tyrell cannot do it alone otherwise, and both young Adepts need to grow into warriors sooner or later. Karis is startled by Isaac's decision to send just the two boys to run this difficult errand so abruptly because of how hard Isaac himself had found running this errand the last time, but Isaac views that to be part of the point of it all; his and Garet's own lives had been changed at the drop of a hat when they originally met Kraden thirty years beforehand. When Karis elects to join the boys' quest, Isaac approves in a way that suggests to Garet that he had planned for all three of the young Adepts to set out together from the start.

Isaac furthermore decides not to arm the children with extra information at the outset, deciding instead to send a carrier pigeon back to Kraden so that the scholar can await Matthew at the nearby lumberjack village Carver's Camp and help the young Adepts chart a more informed course into the unknown. Citing the urgency of the need for him and Garet to continue their studies of the Psynergy Vortexes and Mt. Aleph with Ivan, Isaac silently assumes his post near the cabin and stays there even as Matthew, Tyrell, and Karis are seen off by Garet for their big adventure. Matthew is dejected that his own father is not personally present to see him and his friends off as well.

Isaac is not seen for the rest of Golden Sun: Dark Dawn, and virtually nothing is known of anything in particular that may have happened to him and Garet by the end of the game. Matthew's quest quickly gets sidetracked by agents from a sinister nation into a series of events that portend much darker times for Angara as a whole; when a machine in the ruins underneath Belinsk triggers the dire Grave Eclipse phenomenon, much of Angara is encased within an enormous dome of dark energy that draws out and bolsters monsters. The field of the Grave Eclipse reaches far enough to the west that it technically would encompass Isaac's cabin, raising the possibility that Isaac and Garet are forced to fend off the shadowy monsters on their own.

While Matthew and his expanding party of Adepts search for the solution to dispelling the Eclipse, the only clue that something in particular may have happened to Isaac in their absence is found in Yamata City, where the young seer Himi had been driven into an unnatural sleep for unknown reasons connected to the Eclipse. Eyewitnesses mention that Himi mysteriously cried out the phrase, "Isaac is in danger!" What she was referring to is not revealed.

Matthew's efforts ultimately result in the Grave Eclipse being dispersed, and they also successfully retrieve a Mountain Roc Feather at one point beforehand. After his expanded party of Adepts go their separate ways, Matthew, Tyrell, and Karis make the journey back home to Isaac's cabin. But as they close in toward their home, they realize that Isaac and Garet are nowhere to be seen; instead, a gigantic Psynergy Vortex is now present in the airspace near the cabin. (Dark Dawn's data files show that this scene following the credits features a model of the cabin having been destroyed, but since the post-credits scene never makes it a point to show the cabin on-screen, it is unknown whether this is to be considered canon.)

In the Super Smash Bros. series
Isaac is the only Golden Sun character to make a modeled appearance in Nintendo's Super Smash Bros. crossover series of boundary-oriented fighting games. His original on-screen appearance in the third game in the series, Super Smash Bros. Brawl for the Wii, marked the first occurrence of Golden Sun appearing in a piece of official media since the release of Golden Sun: The Lost Age over five years earlier.

Isaac is one of the computer-controlled "supportive" characters who can randomly be chosen to appear for a player's benefit if the player's own character picks up and automatically uses an item called the Assist Trophy. While Isaac cannot be interacted with or damaged, he will occasionally face the direction of one of the player's opponents and cast the Move Psynergy, conjuring a giant, outstretched palm that projects itself forward in a straight line; any opponent who makes contact with it (even if they are currently invincible from effects such as the Super Star from Mario, known as "Starman" at the time) is knocked back a set amount and can potentially be forced out of the stage's bounds. Unlike most Assist Trophy outcomes, Isaac is one of only six who are not able to appear out of Assist Trophies until specifically unlocked (through playing 200 multiplayer matches, in Isaac's case).

Like virtually all other characters, items, and on-screen elements in Brawl, Isaac's in-game model is featured on a collectible trophy that enshrines the character with an accompanying text description. Isaac's trophy is one of the several hundred that can only be acquired randomly through various game modes such as the Coin Launcher. His trophy's description reads as follows: "A strong-willed Psynergy adept of the bloodline of an ancient race thought to have been lost with the downfall of civilization. He can manipulate earth-based forces and is also a highly skilled swordsman. He sets out to protect a lighthouse that can release the sealed powers of alchemy. In Smash Bros., he uses "Move" Psynergy, which creates an energy field that pushes foes away."

Isaac's cameo role as an Assist Trophy is somewhat infamously cut from the follow-up games for the Wii U and 3DS, leading to Golden Sun having nothing more than two music tracks in the most recent entries at a time. However, Isaac returns in the same role in the version following those up, Super Smash Bros. Ultimate — which incidentally marked the first occurrence of Golden Sun appearing in a piece of official media since the release of Golden Sun: Dark Dawn roughly eight years earlier.

In addition to featuring an updated model, Isaac exhibits several new behaviors that give him a less static presence on the battlefield whenever he is incidentally summoned from an Assist Trophy. He can be knocked aside and sent off the stage's boundaries like a standard playable character; he tries to return to the stage when at risk of being KO'd; he can now use his conjured hand as a clenched fist to damage the summoning player's opponents as if he was using the Pound Psynergy; he can now grasp an opponent in a pair of conjured hands and attempt to send the opponent off the stage's top boundary marker, as if he was using the Lift Psynergy; and he can warp around the stage in an attempt to land moves such as these on opponents more reliably.

Isaac is also one of several Golden Sun characters whose official pieces of promotional artwork are featured as collectible "Spirits", of which Ultimate contains over a thousand. Spirits are packages of bonus statistical enhancements and special traits that can be applied onto characters equipped with them, and they can be leveled up and developed individually; Isaac in particular is one of a proportionally small group of Spirits that can be permanently transformed into stronger and thematically "evolved" versions of themselves through an "enhancement" function, which in his case entails changing his artwork into the one for the adult version of Isaac from Dark Dawn. Isaac is also one of the vast majority of Spirits to each have an accompanying special match scenario that the player must win in order to receive a copy of.

Isaac is provided three voice clips in his initial appearance in Brawl, which are recycled for his return appearance in Ultimate. Consisting of two battle yells and the word "Move," they are provided by female Japanese seiyu Aya Hara, who also voiced Krystal from Star Fox in Brawl and Star Fox Assault for the GameCube.

Trivia

 * Isaac's emblematic scarf appears to switch the shoulder it is draped over between his official pieces of promotional artwork and his in-game appearances in both Golden Sun and Super Smash Bros.. Similar inconsistencies occur regarding the placement of his sword on his back, making it difficult to determine his dominant arm. It is uncertain whether this is intentional.
 * Isaac can instigate a hidden "bad ending" extremely early in Golden Sun when he is asked in Vale's sanctum whether he will take responsibility for the fate of the world. If he chooses no, he will be free to walk around the sanctum while the other NPCs, such as Garet and Dora, express that they understand Isaac's decision. He can talk to the Great Healer so that he can take back his decision, but otherwise, if he leaves the sanctum despite the Great Healer's warning that he cannot take back his decision once he walks out, the screen will turn gray and a piece of narrative text will say, "And so the world began drifting toward its fated destruction..." Then, a prompt will allow the player to return either to the scene where the question was originally asked or to the game's File Screen.
 * Following the reunion between Isaac and Felix's parties at Contigo late in Golden Sun: The Lost Age, Isaac joins Felix's party on the latter's Lemurian Ship; the Lemurian Ship that Isaac had used for himself up to that point is never mentioned or shown on-screen and has seemingly vanished.
 * One common fan explanation is that Alex may have stolen it at around this time to bring himself back to Angara and Mt. Aleph in time for the Golden Sun event; the means by which he travels from the island continent of Atteka to Angara is never explained otherwise. This idea would require Isaac to have left his own Black Orb on his own Lemurian Ship so that an Adept like Alex could sail the ship successfully, but Isaac's black orb will (uselessly) be part of his inventory if the player uses the game's Password data transfer feature to its fullest extent so that the party's inventory will be a copy of what it was at the end of a save file on the previous game. Since Isaac will not have his Black Orb with him in a game of The Lost Age that is enhanced with nothing higher than a Silver-rank password (if it is enhanced with a password at all), and since Felix never has any need to bring his own ship's Black Orb with him on the many occasions he disembarks, it can be assumed that the Black Orb being part of Isaac's party in either a Gold-level password or a Game Link Cable-based transfer is a development oversight.
 * The August 2009 issue of the Official Nintendo Magazine published in the United Kingdom made the erroneous claim that the main playable character seen in the E3 2009 trailer for what was known at the time as Golden Sun DS was Isaac himself, rather than a descendant of Isaac as confirmed by the trailer's accompanying press release.
 * In another gaffe committed by media outlets pertaining to Isaac, the product listing on Amazon.com's UK division for Golden Sun: The Lost Age erroneously describes Felix as Isaac's "long-lost brother", which humorously would have meant that large swaths of Golden Sun's passionate fan-fiction-writing base were unwittingly penning incest fiction when writing about romantic relationships between Isaac and Jenna, Felix's sister. In a slightly ironic coincidence, Golden Sun: Dark Dawn would later confirm Isaac and Jenna's status as a married couple, which technically makes Felix Isaac's brother-in-law.
 * During the prologue segment of Golden Sun: Dark Dawn, Isaac and Garet become the first computer-controlled party members in the series.
 * A woman at Patcher's Place states that Isaac was a ladies man back when he was younger. This parallels how Felix was described as a ladies man in his own right in the village of Prox.

Name origins and meanings

 * English: Isaac. Isaac is a name of Hebrew origin, meaning 'He will Laugh'. Isaac in the Bible is one of the Patriarchs of the Jewish, Christian and Muslim Faiths; this seeming usage by the English localization of a religious element may be reinforced by it also granting Mt. Aleph a name that references first letter of the Hebrew alphabet, and Dark Dawn would later give his son the name Matthew — which is also a name that appears in the Bible. On the other hand, "Isaac" may also reference the physicist Isaac Newton, who incidentally wrote many dissertations on the real-world protoscientific field of Alchemy.
 * Japanese: Robin. Robin means 'fame' in Old German. A Robin is a bird who in folklore is connected to charity, compassion, both good and bad luck and omens of winter and death.
 * French: Vlad. Vlad is short for Vladislav, which is a Slavic name and means 'to rule with glory'. The most infamous Vlad is Vlad III/ Vlad Tepes. This may be a nod to the Ragnarok/Odyssey Psynergy that summons swords to impale a foe.
 * Spanish: Hans. Hans is the German equivalent to John, which means 'God is generous'. One could consider this an interesting name choice as Isaac is gifted with part of the powers of Alchemy.

Side quest roles

 * Each of the bonus events that take place in Golden Sun: The Lost Age on account of Isaac's party having accomplished certain feats in a game file for Golden Sun that was used for the password data transfer system can be seen as a manifestation of Isaac gaining at least a small measure of fame as his quest proceeds.
 * Shortly after the eruption of Mt. Aleph propels Isaac into his quest across Angara, he and Garet help Ivan bring the local Vault gang of thieves to justice and have them jailed. When Isaac is able to return to Vault much later in his quest, he can learn from talking to the town's mayor that the thieves managed to bust out of imprisonment and are now seeking revenge against him. During Felix's quest in The Lost Age, the thieves will accost Felix's party upon hearing that Felix is affiliated with Isaac somehow and will attack him to vent their frustrations with Isaac; when they are beaten back, the thieves will rush off in apology and leave behind the Golden Boots equipment. (Since the thieves break out of jail on their own during Isaac's absence from Vault, there is no apparent reason why the thieves' opportunity to encounter Felix later would be dictated by whether or not Isaac speaks with the mayor about the thieves' breakout and departure from Vault after the fact.)
 * One of Isaac's roadblocks is created for him by his enemies in the region of Angara encompassing Xian when they cause a landslide at Alpine Crossing. Because Isaac learns from a young woman named Feizhi that her friend Hsu has been caught up in the landslide and is now trapped under the rubble, Isaac may decide before entering Lamakan Desert to briefly enter the crossing from the opposite direction and use the recently discovered Lift Psynergy to free him, allowing Feizhi to treat Hsu back at Xian. Feizhi will become thankful enough to Isaac that her feelings for him become more amorous over time — to the point that she decides to make a good-luck charm in the form of the Golden Ring. In The Lost Age, when her power of prediction informs her that a group much like Isaac's will appear in the nearby village of Champa, she heads there with the assumption that it is Isaac so that she may give it to him. Though she is disappointed when she finds Felix's party instead, she nonetheless gives Felix's group the Golden Ring when Kraden promises to tell Isaac how she feels (though nothing comes of this thread even after Isaac's party joins Felix's late in the game).
 * If Isaac manages to take first place in the Colosso Finals instead of the second-place position that is what is merely required to advance the first game's story, he will make a relatively prominent name for himself as a gladiator and earn the disapproval of the three particular gladiators he defeated: Azart, Satrage, and Navampa. In The Lost Age, Felix will encounter the other three gladiators who did not win the competition — Morgan, Dekka, and Galahad — who remark that Isaac may be in trouble because the other three are now actively seeking vengeance against him. The three defeated gladiators will eventually come across Isaac's expanded group by chance in Shaman Village Cave and relay their suspicions that Isaac's victories against them was rigged in some way, and they attempt to overpower Isaac's party in what they see as an unofficial rematch. The gladiators are easily defeated again and will take Kraden's point that Isaac's Psynergy powers are a warrior's skill, and after apologizing and receiving Isaac's forgiveness, they give him the Golden Shirt and suggest that Isaac can compete against them again in the next Colosso.
 * If Isaac elects to lead his party back from Tolbi to Angara so that Ivan may rescue his adoptive father Hammet from Dodonpa's grasp in Lunpa Fortress, they will get some additional clues as to how the Shaman's Rod is to be used (they will not personally be able to use them once Felix's side takes the Shaman's Rod, but the player will be all the more informed on where the Shaman's Rod is to be brought by Felix's party in The Lost Age). More directly, Hammet having been safely returned to his home city in Kalay will be the reason why an emissary will deliver an Orihalcon to Isaac in Atteka shortly after Isaac's party joins Felix's.
 * Late in Isaac's quest, he may pursue the optional course of discovering and exploring Crossbone Isle, the uncharted island cave in the Karagol Sea that is rumored to contain all manner of buried treasures. Should Isaac and his party prove themselves powerful and capable enough as Adepts to survive the island's entire repertoire of traps and exotic monsters and even defeat the terrifyingly powerful ancient ghost pirate protecting the treasure, he will be able to pick the island clean of its highly desirable loot. Following Isaac's expedition, certain circles among Weyard's pirates will somehow learn that Crossbone Isle had been completely plundered by a man named Isaac. At any point in The Lost Age after Felix inadvertently allows Briggs to flee Alhafra with its vaunted sailing ship, his party may find a duo of pirates in Alhafra's inn discussing how Isaac's defeat of the ghost pirate technically makes him the leader of pirates everywhere by right. The two pirates will leave the inn in hopes that they can find what they presume to be Isaac's accomplished pirate crew. (This scene can take place after Isaac's party has already joined Felix's, in which case, the pirates will be unaware that they are leaving behind their new "leader.") As of Dark Dawn thirty years after the fact, however, there is no mention of Isaac having acquired any followers among pirates.

Quotes
As Isaac is depicted as a silent protagonist throughout the first Golden Sun, the most expressive he ever becomes is when he "says" "!!!" in response to an utterly staggering development late in the game. Golden Sun: Dark Dawn's encyclopedia entry for Isaac:


 * This Earth Adept left his hometown of Vale 30 years ago — and returned to find it destroyed by the Golden Sun event.
 * He lives in the cabin that looks upon distant Mount Aleph, where he trains his son, Matthew, in the use of Psynergy.

In fan circles
As the main protagonist of the first game, Isaac's romantic shippings with female characters had been fiercely debated since the Golden Sun series started. Up until the release of Golden Sun: Dark Dawn roughly seven years after the Game Boy Advance duology, the most prominent point of contention pertained to who should be counted as his love interest: Jenna, his childhood friend from his hometown who he goes on a dangerous quest to save when she is taken hostage, and Mia, the only female party member in his group of traveling Adepts. Large volumes of fan fiction had been written about both of these scenarios (coined "Valeshipping" and "Mudshipping," respectively), so the community was split when Dark Dawn confirmed that Isaac would have a son with Jenna.

As Isaac completely lacked a speaking role throughout the first game, some demographics among the fan base objected to the personality he was given when he was granted a prominent speaking role in the second game because his personality was far less discernible beforehand. Particular attention was paid to the rather curt tone he takes with his earliest lines when first seen in the second game caught up in a harrowing situation.

Isaac has been featured in various popularity polls on GameFAQs since at least 2007. He was unable to make it past the first round in the polls for the years 2007 and 2008, but in the 2010 poll he was able to outvote Professor Layton to go against the intentional joke inclusion L-Block from the Tetris property (which he lost against).

Isaac is routinely discussed as a potential new inclusion on the main roster whenever a Super Smash Bros. title is announced and enters its pre-release cycle. Despite the Golden Sun series seemingly being decided by Nintendo and/or director Masahiro Sakurai to be a "dead" property when Isaac's small role in Brawl was followed up by nothing Golden Sun-related at all appearing in the Wii U and 3DS follow-ups, there was a noteworthy outcry among reaction videos when Isaac was revealed to be "merely" returning for Ultimate as an expanded version of his previous Assist Trophy role. Prior to the Ultimate development, Smashified — where community members create images resembling official renders of playable Smash Bros. characters — posted a render for Isaac on August 20th, 2015.