Bahamut Prime

Bahamut Prime is the final boss of the Final Coil of Bahamut, as well as the entire Coil storyline. He is fought in Turn 4 of the Final Coil.

Bahamut Prime is notably smaller than his full physical body, but it is heavily implied that this is because Bahamut Prime is the elder primal's true aetherial form fought in the aether realm, considering how it is fought in a location called The Burning Heart.