The game's main antagonist, Genesis Rhapsodos, was created as a collaboration between Camui Gackt and Hideki Imaizumi, the game's producer. Gackt's original involvement with Square Enix was in singing the theme music for Dirge of Cerberus: Final Fantasy VII, "Redemption", and appearing as a minor role in that game playing Genesis. Imaizumi thought such a passing role was a waste and asked for him to have more involvement, and asked for his help in coming up with Genesis's design, describing everything from his attitude to his clothes.
Contributed by DrakeVagabond