Ancient Devil

The Ancient Devil is an optional boss monster located and fought at the end of the optional Otka Island dungeon in Golden Sun: Dark Dawn. The Ancient Devil awaits players willing for a battling challenge and guards the summon tablet containing the Catastrophe summon sequence, basically fulfilling the same role the Sentinel did in Golden Sun: The Lost Age.

Background and story
The Ancient Devil, resembling a winged goat-like demon armed with a grimoire, does not have any bearing on the game's actual story, nor is any background information provided. It is a powerful entity standing guard within the deepest depths of Otka Island, in the unmapped dungeon section that can be accessed after the player has obtained the Sol Blade.

In the event any group of intrepid and capable Adepts discovers the secret dungeon and successfully traverse a long skull-shaped maze, the Ancient Devil and the summon tablet await in a dark torch-lit chamber at the end. The Ancient Devil will decend down and introduce himself to the party before going on the offensive:


 * "I am the guardian of wind. Ye who desires more power must first reveal thine own."

As a boss
Statistically, the Ancient Devil has 11,783 Hit Points, 400 Psynergy Points, 482 Attack, 239 Defense, 330 Agility and 50 Luck. Concerning elemental attributes, it has a Venus resistance of 180, a Mars resistance of 150, a Mercury resistance of 130, and Jupiter resistance of 72 and uses its available Venus based attacks with a Venus power rating of 110 and its Mars based attacks with a Mars power of 105.

The Ancient Devil has access to the following moves:
 * Demon Sign: Used 2 out of 8 times, this ability allows the Ancient Devil to take control of one of the player's Adepts. If the Ancient Devil is felled, so too will this Adept. If the Adept is felled, it will rejoin the party in KO'ed condition. The Ancient Devil will only use this move to take control of one Adept at a time. It will usually possess the adept that has the highest agility in the current team.
 * While under the Ancient Devil's control, the adept is often ordered to attack, occasionally use Psynergy, and is capable of using your summons against you. If the Adept has any healing items in his or her inventory, he or she will use them on the boss, but never themselves.


 * Attack: Used 1 out of 8 times, this is this boss' standard physical attack.


 * Curse: Used 1 out of 8 times, this is a Psynergy spell that may inflict the Death Curse condition at one target and consumes 6 of its user's PP.


 * Dire Inferno: Used 1 out of 8 times, this is a Psynergy spell that conjures a massive ornate shape to drop a big fireball, resulting in a huge explosion. It deals a Mars-aligned attack with a Mars power rating of 200 and a range of 5 targets. This consumes 32 of its user's PP.
 * Psy Drain: Used 1 out of 8 times, this is a Psynergy spell that attempts to steal one target's PP with a Jupiter power rating of 20. Consumes no PP.


 * Undead Might: Used 1 out of 8 times, this is a Psynergy spell summons a huge skeleton warrior to hit the target with powerful force. It deals a Venus-aligned attack with a Venus power rating of 250 to one target and consumes 30 PP upon usage.


 * Haures: Used 1 out of 8 times, this is a summon sequence that calls the blue-skinned demon with red nails and fangs to wreak havoc upon the party. This deals a Venus-aligned attack with a Venus base power of 270 with additional damage equal to 15% of the victim's maximum HP meter. All targets also have a chance to get inflicted with the Deadly Poison condition.

Felling the Ancient Devil nets the party 55,216 EXP, 3,438 Coins, and the summon tablet it was guarding becomes approachable. If the player manages to land the finishing blow on the Boss an offensive Jupiter Djinni, its rewards increase to 71,781 EXP and 4,469 Coins.

Strategy
The key quirk to this fight is that one of your own Adepts will be fighting against you almost the entire fight. The possessed Adept will usually just attack, though will sometimes use some of his or her own Psynergy and if he/she has some healing items in their inventory, they will often use those on the boss. However, the most dangerous aspect of the possessed Adept is that they can (and will) use your summons against you, drawing from your pool of stand-by Djinn. Furthermore, they will summon with only a couple of Djinn on standby, even if it's an entirely incompatible summon (there is nothing stopping Angel Rief from summoning Kirin). As such, if you do plan on summoning, plan on unleashing no more than a couple Djinn at a time, and summon that summon in the very same turn as the second Djinni being unleashed, otherwise you run the risk of the summon being used against you. If you want to open with a powerful volley of summons, place your fastest characters in the front line and put enough djinn on stand by in such a way that they can all be used in a single turn.

There is nothing stopping the boss from possessing lethal characters, such as Savage Fiend Sveta (which you JUST put into Beastform), or Master Matthew with mastered Sol Blade and 99% unleash chance; or highly useful characters like Pure Mage Rief. As such, have more expendable characters in the front line and switch in such key assets after the first round, as the boss will always use Demon Sign as soon as he can if he does not have a possessed Adept (this includes his very first move).

Throughout the fight, focus your offense on the Boss. The possessed Adept will go down either to the area of effect of your attacks or will go down once the boss is dead. Since the boss will always possess a new Adept as soon as the current possessed one goes down (putting the now KO'd Adept in the back line), you should try to avoid taking out possessed ally unless he or she is going to wreak havoc on you (such as one of the aforementioned examples). With the exception of being able to summon Haures at will, he is not the most damaging of bosses, and a character or two constantly casting Wish should be more than adequate to keep your party alive. Try to boost your resistances and defenses to mitigate Undead Might and Dire Inferno (his Attack shouldn't be that much of a threat). The fight can be a long one (as it might be difficult to pull off the more powerful summons), but isn't overtly difficult.

Trivia

 * The Ancient Devil bears a striking resemblance to Baphomet.