Agatio

Agatio is a Mars Adept who, along with his partner Karst, plays the role of one of Felix's primary antagonists in. He is described as second in power only to Saturos in the military hierarchy of his home village, Prox, and he is perhaps even more obsessive in comparison about Prox's elevated position over world affairs once Saturos' quest to break Alchemy's seal is complete. While pursuing this goal with Karst, Agatio also helps Karst search for her sister Menardi and collaborates with her to put Isaac to death once she finds out from Felix that Menardi and Saturos both died at Isaac's hands in the first.

Biography
Agatio hails from the village of Prox, the northernmost settlement on the world map, which is located near the edge of the world at the north end of the wintry Northern Reaches. Agatio and the other Proxian villagers have a strong affinity to the Mars element because they have descended from the ancient Mars Clan, which had historically based themselves around Mars Lighthouse nearby. This may relate to their somewhat dragon-like bodily features and their natural immunity to the biting cold of their environment. Agatio is regarded as the second strongest warrior currently in Prox's employ, with only Saturos being higher in rank and apparent authority.

Right before the events of Golden Sun begin, Agatio and Karst stay behind in Prox as Saturos departs on a quest handed down by Prox's leadership to raid Sol Sanctum for the four Elemental Stars and then travel across the world, lighting the Beacons of each of the four Elemental Lighthouses scattered across the world. The Proxians are aware that breaking the seal on the long-dormant force of Alchemy in this manner will save their village from the brink of extinction, for Gaia Falls, the edge of the world up north, is inexorably encroaching upon Prox. Joining Saturos on this quest are Karst's elder sister Menardi and the young Venus Adept Felix, whom Prox has coerced into collaborating with the quest by keeping his parents all but captive at Prox. Agatio and Karst may or may not be aware that a fourth Adept, Alex, is also a part of Saturos' company collaborating with them to help release Alchemy to the world.

"Scaring" Felix into action
Through circumstances that are not disclosed to the player, Agatio and Karst end up sailing out of Prox, both intending to search the entire world for Menardi to confirm her well-being. They have apparently reached the Eastern Sea right around the time the climax of the first Golden Sun takes place, when Saturos and Menardi's efforts to light Venus Lighthouse bear fruit. This is because the tower's Venus Beacon indirectly triggers a massive tidal wave that impacts much of the southwestern Eastern Sea, driving the island continent of Indra between the continents of Gondowan and Osenia; as a result, the naval route back to the Western Sea and to Prox are blocked off by natural obstacles. Agatio and Karst presumably spend a while searching the lands accessible from the Eastern Sea in search for Menardi.

Eventually, the duo beach their ship on Indra and split up in their search, with Agatio heading up north into southern Gondowan to check a village named Naribwe. When he asks an old man there whether he had seen a woman named Menardi and doesn't get a worthwhile answer, Agatio violently shoves him to the ground and storms off. He eventually returns to Karst's ship and waits for Karst to return — but when she does, she bears dire tidings: Karst happened to come across Felix in the village of Madra, who had been leading his own company of Adepts across the world seeking to finish Saturos' original quest ever since Saturos and Menardi died fighting a group of rival Adepts led by one Isaac. Naturally, Karst has sworn to kill Isaac out of revenge.

The Mars Adepts then meet with Alex, who had broken away from Felix's group out of a belief that Felix would be ineffectual without Saturos' direction. Agatio and Karst presumably catch up on matters like how Isaac has sworn himself to take back the Elemental Stars and stop the remaining Lighthouses from being lit, and that Isaac currently has the Mars Star while Felix carries the Jupiter Star. Joining the duo on their ship, Alex uses what Agatio personally considers his "remarkable foresight" to anticipate that Felix will stop at the coastal pirate village of Champa and wait for them there. Alex introduces Agatio and Karst to Felix in this manner to threateningly "encourage" Felix to keep his priorities focused on reaching Jupiter Lighthouse instead of leisurely exploring the Eastern Sea.

However, Alex makes clear to his two "associates" that Felix is ultimately the best-equipped among everyone to open the way to the Western Sea and climb Jupiter Lighthouse, regardless of what Agatio and Karst might think. Alex had decided this ever since Felix resourcefully retrieved a stolen item from the warlike Kibombo tribe without recklessly using Psynergy to terrorize them. Meanwhile, Alex surprises the duo by speaking dimly of the deceased Saturos and Menardi's struggles to intellectually surmount the riddles of the two Lighthouses that have been lit thus far. Alex smugly affirms it when Agatio accuses him of suggesting that all four of the Proxian Mars Adepts are "simple brutes, incapable of logic and intelligence." Despite this blatant insult, Agatio refrains from showing anger and instead acknowledges the logic Alex poses that flexing their muscles and "scaring" Felix into action will ultimately lead to the quest's expedient conclusion.

Though Agatio, Karst, and Alex presumably follow Felix across the ocean to ensure the latter's voyages across the Eastern Sea are always spurred on by psychological pressure, they apparently never feel any need to cross paths with Felix for the remainder of the latter's time spent exploring the sea. Felix and his party are free to pursue their goals of developing their powers and fighting potential, and they eventually leave the hidden island society of Lemuria with a powerful "grinding" Psynergy that allows them to bore their way through the blocked-off naval route into the Western Sea.

Fallout at Jupiter Lighthouse
By the time Felix's party has reached Atteka and begun climbing Jupiter Lighthouse, Agatio, Karst, and Alex have landed on the continent and soon follow his party inside. Right after that, Agatio's side learn that Isaac's party has also entered the Lighthouse, intent on putting a stop to Felix's efforts to light Jupiter Lighthouse. Knowing from Alex that one of Isaac's companions, Mia, is a Mercury Adept who potentially threatens the Mars Adepts the most, Agatio and Karst set up a trap at one of the tower's outdoor balconies, and they set it off just as Isaac's group traverses a retractable bridge. This causes Mia to fall onto another ledge underneath, and Garet ends up falling after her while trying to save her. Agatio and Karst are pleasantly surprised that their enemies have been divided in half, which means they now only have to deal with Isaac and his remaining companion, Ivan.

Agatio and Karst soon step forward to introduce themselves to Isaac's party, and Agatio describes Isaac as both a hindrance to their side's efforts to break Alchemy's seal and someone who has done Karst a great wrong. They also describe Prox as standing to "recover its lost power" and proclaim that all of Weyard shall "kneel" before their village once it has done so. Since the duo aren't even interested in having a fair two-on-two fight with them, they also reveal they had allied with Alex to help them... but they realize at that moment that Alex is nowhere in sight and has abandoned them to fight on their own. The duo consider this a betrayal on Alex's part, and Agatio claims he was always planning to put down the sneering Mercury Adept the same way they plan to put down Isaac.

The Mars Adepts fight Isaac and Ivan in what is, for them, a surprisingly fierce and close battle, despite having properly matched themselves so that Agatio personally focuses on Isaac and Karst is left to duel Ivan, but Ivan's faltering distracts Isaac and results in both young Adepts getting defeated. Agatio gloatingly lectures to Isaac that his inability to prevent concern from distracting him in battle is what led to his loss. Before the injured Agatio and Karst move to kill Isaac, they are surprised when Felix's party comes by and stands up to them, and they are displeased that he has evidently not set off the Jupiter Beacon yet. Despite Agatio reasoning that Isaac cannot be allowed to live because of how powerful he has proven himself as their shared enemy, Felix forces the weakened Mars Adepts to stand down, and Karst accepts despite viewing this as a betrayal. Agatio is surprised by this and reminds her that Isaac killed her sister, but she explains that she is not so blinded by her seething rage that she cannot see that the duo will be destroyed if they make a move.

Agatio accepts giving up but vows that "this is not the end," and he first has Felix swear that he will follow them to the aerie and light the Jupiter Beacon without staying behind to help Garet first. Agatio also makes Felix take the Mars Star off Isaac's person, boasting to their admittedly surprised audience that the Mars Adepts' presence here wasn't purely about simple revenge. Felix and his companion Piers follow Agatio and Karst up to the aerie while their other companions Jenna, Sheba, and Kraden tend to Isaac's party, and Felix lights the Jupiter Beacon under the duo's watch.

Agatio and Karst then inform Felix that they see no need to indulge his traitorous tendencies anymore because the final Beacon can be safely left to them. Because Mars Lighthouse lies near Prox and is seen by the duo as presumably easy enough for them to scale and light on their own, Karst steals the Mars Star from Felix, and she and Agatio announce that it is time for Felix to die. When Piers asks what would happen to Felix's parents in that case, Agatio stresses that, unlike Felix, they and the rest of Prox actually keep their promises and will release them as agreed. The Mars Adepts cruelly gloat that the parents might have to live their lives in Prox anyway because Felix won't be alive to take them back to their home village; on this note, the duo attempt to execute Felix and Piers, but Jenna and Sheba arrive in time to reinforce Felix's numbers and balance out the fight.

This battle may result in one of two scenarios depending on whether the player wins or loses as Felix. If Felix's party manages to overpower the duo and leave them lying prone on the ground, Agatio commands the victors to finish them, showing not an ounce of fear. Even after Karst suggests that Prox may retaliate by putting the captive parents to death if she and Agatio die at this juncture, it is up to the player whether Felix would be inclined to let the duo live or not. Regardless, Alex suddenly arrives and attempts to convince Felix that taking Karst's statement as a hollow bluff is too great a risk considering the lives of his parents are at stake. Since Felix presumably would leave the duo behind otherwise, Alex heals both Karst and Agatio just enough that they can take Jupiter Lighthouse's escape elevator with him; the duo are not pleased with Alex essentially refusing to help them defeat Felix's side.

If Felix's party is the side that gets defeated and nearly killed, on the other hand, the Mars Adepts express astonishment at both the power of their opponents and the fact they still all survived the duo's strongest assaults. Agatio has the presence of mind to warn Karst that they must leave before Isaac's recuperated party arrives, but Karst remarks that Felix has to die for his treason. Alex arrives to tell her off for spending too much time on "petty grudges"; though the Mars Adepts now view him as their enemy after abandoning them, Alex convinces the thoroughly exhausted duo that they are in no condition to fight him, either. Agatio listens to reason and tells Karst that they have no choice but to escape with the elevator, a decision that Alex praises, and the three Adepts flee the tower. Regardless of which of these two scenarios is viewed by the player as canonical, Agatio and Karst later part ways with Alex.

Final defeat
Agatio and Karst, having at least seen to the lighting of Jupiter and procured the Mars Star by this point in their campaign, make the journey back to Prox intent on finishing Saturos' original quest by lighting Mars Lighthouse. They manage to return to Prox despite the sea route back into the Northern Reaches remaining blocked off by a thick ice wall in-game. As if acting out of spite, the duo tell their countrymen that Felix "ran away" because their quest was "too dangerous," and Prox soon sends the duo to Mars Lighthouse as the village's strongest warriors who are still alive. However, as they explore the halls of the ancient tower, the Wise One — the eye-like entity that originally tasked Isaac with stopping the release of Alchemy — suddenly approaches them. The being perhaps unilaterally tells them that they "lack the will to go any farther," and the duo are suddenly transformed them into mindless Flame Dragons and sealed in a slab of ice.

Meanwhile, Isaac's party joins forces with Felix's because an oracle had informed them that Agatio and Karst will fail to light the Mars Beacon because a "powerful force that does not want to see Mars rekindled" stands in their way. The eight Adepts composing this expanded group make the journey into the Northern Reaches and pass through Prox, and they receive the villagers' blessing to enter Mars Lighthouse and take the Mars Star from Agatio and Karst, whom the people acknowledge have evidently failed in their duty. The Adepts soon find the two dragons and release them from their icy prison, and the creatures immediately attack the party as if driven by instinct. Once Felix's side puts the two dragons down, they suddenly transform back into the dying forms of Agatio and Karst, who only vaguely recollect fighting Felix. The duo realize that they are on the verge of death because they can feel the cold of their surroundings despite their natural-born immunity to cold temperatures.

The Mars Adepts then realize Felix is in the room with them, and Agatio weakly remarks that their "luck hasn't entirely run out yet." Despite having very violently treated him as their enemy up until this point, they suddenly take a much different stance toward him and plead with him to light the Mars Beacon on their behalf, and Agatio weakly places the Mars Star next to his body on the floor. Felix agrees to this and takes the Mars Star, and and he and his allies have little choice but to leave the two behind and climb up to Mars Lighthouse's aerie with it. Agatio and Karst struggle to stay alive until they have seen that the Mars Beacon is lit; though this eventually happens, it only comes after Felix's extended party has to contend with the Wise One as well.

The breaking of the seal placed on Alchemy, which is concurrent with the release of elemental power throughout Weyard, saves not only Prox but also the rest of the world from their eventual extinction. Prox's villagers express gratitude to Felix and Isaac's company for both saving their village and bringing about what is hopefully a new golden age for Weyard, and they are regretful that they had to treat Felix's parents as prisoners to coerce Felix's involvement in Saturos' quest originally. They also pay their due respects to the now-deceased Agatio and Karst despite acknowledging that the two were "a little obsessed."

As a boss in
Agatio makes his sole in-battle appearance as one of a pair of boss-style enemies fought together in one battle at the end of Jupiter Lighthouse late in the game, accompanied by Karst.

This battle is scripted to transpire after a cutscene that takes place once you choose to cast the Jupiter Star into the well at Jupiter Lighthouse's aerie. Out of all the boss encounters in the GBA duology, several unique aspects come into play when fighting Agatio and Karst. First, you must fight two turns against them with just a party consisting of Felix and Piers, and a cutscene will then interrupt the battle that will add Jenna back to your party. A second two-turn battle will then take place, and then the fight is interrupted again to allow for Sheba to arrive and add herself to your party. The third battle sequence that ensues is the "real" boss battle.

Attacking Agatio and Karst is pointless until Sheba has joined because they will refill their HP between cutscenes, so you might as well strive to stay as healthy as possible so that the party has suffered minimal damage by the time the real battle begins. If both Felix and Piers are somehow knocked out during the first two-turn phase, the cutscene where Jenna joins still takes place, and the next two-round phase occurs with both male party members downed and only Jenna actively battling. If she is also somehow knocked out before Sheba's arrival is scheduled to take place, the cutscene for her takes place anyway, and the third and final version of the battle begins with her being the only one still alive.

Unlike most other boss encounters in the Golden Sun series, the player is free to lose this battle without putting a stop to the story. Losing the third, main battle will cause a different post-battle cutscene to take place, but Felix's party will be revived nonetheless and be allowed to depart Jupiter Lighthouse for Contigo as normal. That said, winning the battle is obviously preferable in at least the short term because the party will be rewarded with a lot of EXP and Coins, and the game's first available Dark Matter will automatically be dropped by Karst.

Between the two opponents, Agatio has about 33% more health, and his move arsenal is focused on high-damage attacks that include a rare instance of a multi-target elemental physical attack, a very damaging single-target Psynergy, and a meteor-like summon sequence that scales up its damage the more maximum health the party has. Agatio can also deal a physical strike that may Stun the target. Despite arguably dealing more damage to the party than his partner, players are recommended to focus down Karst first because she undermines the party with tricks like temporarily putting the party's Djinn into recovery, clearing away their buffs with Break, and occasionally inflicting instant death. Once Karst is gone, Agatio will be much easier to handle; even though he will still pile on a lot of damage to the party, area-of-effect healing Psynergy like the Aura Psynergy series will keep the party topped off safely.

Agatio is especially likely to be affected by Attack-lowering effects. His statistics are as follows:

Agatio uses the following battle commands with :

In addition, the game's internal bestiary includes a version of Agatio that has 200 more Agility, 76 more Attack, 72 more HP, 53 more Defense, and can only use Rising Dragon. This version appears only in the brief "cinematic battle" that takes place on Jupiter Lighthouse, when Agatio casts Rising Dragon to down Isaac.

Trivia

 * Each of the three Golden Sun titles' primary villainous male-and-female duos share their own thematic naming conventions. Agatio and Karst appear to be named after geology terms, with Agatio named after agate, a particularly colorful variant of crystallized silica. Karst is named after karst topography, which is where subterranean cavities can form within dissolving bedrock.
 * When Agatio and Karst are waiting at the aerie of Jupiter Lighthouse for Felix and Piers to use the Jupiter Star, both have dummied-out lines of mental dialogue that cannot be seen in normal gameplay because the Mind Read Psynergy is currently unusable on account of Sheba not being in your party at that moment. If a hacking device is used to give Felix or Piers Mind Read, Agatio is revealed to be thinking, "Do even think about resisting us... We have our own ideas about that. Once the beacon is lit, your usefulness will have run out for good." Presumably, the obvious typo with the first word (which should be "Don't") only exists because the line was never double-checked as a line expected to be read by players. The error aside, it is unknown why the developers would have even inserted and written these text strings because it is established in-universe that Adepts can tell when the Mind Read Psynergy is being used to read their thoughts, allowing them to either tell off the player or hide their intentions with a different "mentally spoken" statement.
 * The game's other prominent instance of Mind Read dialogue that cannot actually be read without hacking in the Mind Read Psynergy occurs at Prox, which also concern Agatio and Karst. During the epilogue sequence, when Felix and Isaac have an opportunity talk to each of the villagers, every villager has their own hidden string of Mind Read-accessible text. One of these thoughts indicates that Agatio and Karst are apparently understood by the villagers to have been "defeated by a monstrous dragon" that Felix subsequently beat, which is very different from what had actually happened — that the duo were themselves transformed into monstrous dragons that Felix had to slay.
 * In, the Psynergy Training Grounds obstacle course played through early in the game has the player shooting Fireballs to burn up posters of Agatio and Karst, which represents Felix's battles against them both atop Jupiter Lighthouse and within Mars Lighthouse.

In fan circles
Agatio is easily one of the less popular Golden Sun antagonists because he largely serves as little more than the brutish muscle accompanying Karst throughout her latter three appearances on-screen. He lacks a self-evident personal motivation beyond his duty to help Karst carry out her personal vendetta, and there is scarcely any opportunity to interpret a deeper relationship between the two than being her straightforward comrade-in-arms. His national pride and obsession to see his people reign over the rest of the world once Alchemy is unleashed is also largely unexplored. His sudden willingness while dying at the end of the second game to give Felix back the Mars Star so that the latter can finish the quest is somewhat overshadowed by the better-received Karst doing the same thing in the same scene.

Much fan fiction has accepted the challenge of humanizing Agatio even when one considers that there seems to be no romantic chemistry between himself and Karst — though of course, there is a shipping genre for their pairing: "Dragonshipping." Some also point out that Agatio, in accepting that Alex is merely using him to pressure Felix into getting a move-on with his quest, retains his dignity by not bothering to care about Alex's smug behavior and stressing that the Lighthouses being lit is what matters in the end.