Anima
Aquired at: Baaj Temple
Unique Attack: Pain - single enemy, large chance of instant death
Overdrive: Oblivion - all enemies, multiple non-elemental attacks
Anima is originally seen as the creepy Aeon summoned by Seymour but can later be aquired by the party on a sidequest. In order to gain this aeon one must collect all 6 treasure chests from each Cloister of Trials then return to the Baaj Temple and enter its underwater sector. Here you may approach the Anima statue's thus unlocking the doorway to the most devastating Aeon in the game.