Bahamut

Bahamut is the lord of all good dragons, and the master of the Skies. For the longest time he existed as the bone dragon Cassius while an usurper, his child with Tiamat, claimed his divine spark. In the aftermath of The Muse War, with the help of his Platinum Legion, the spirits of all the knights that had hunted the usurper, he tore his divine mantle away and reclaimed it.

His bone form remained the deity Cassius. The remains of his usurper became the dragon god Parttich. He opposes Tiamat, but still longs for her company, and two maintain strained relations.