The last boss in this game is very weird one. The size is so small, but the power is so cool. When the battle begin, cast 'Reflect' magic on it, because it will use 'Full-Cure' on it after each attack which cure 9'999 HP. When you reach Yuna's turn, cast 'Reflect' on all party members too. Use Tidus and Auron to attack and use Yuna's 'Holy' to attack it.