Bahamut (Final Fantasy XIII boss)

Bahamut is a boss in Final Fantasy XIII. It is Oerba Yun Fang's Eidolon, and emerges through her l'Cie brand while the group are traveling through the The Fifth Ark - Vaults. Like all Eidolons, Bahamut inflicts Doom at the beginning of the battle, and instead of being defeated, Fang must fully fill Bahamut's Gestalt Bar.

Bahamut is an aggressive Eidolon, initially targeting Fang with physical attacks followed by Whirlwind on the party. Libra will reveal that hitting him to get chain bonuses and switching to Saboteur to debuff him will satisfy him. You will need to do both over the course of the battle, as well as defending the party as Sentinal to fill his Gestalt Bar faster.