It's a pretty ironic cover name for him, though. He's corrupted by
Reshef, a dark being who absorbed even the God Cards' power. The main
character eventually restores the God Cards' power, frees Pegasus from
Reshef's influence, and duels Reshef himself. After the duel, however,
he attempts to possess Pegasus again. (He "found the darkness in his
heart") He thinks he's unforgivable for the crimes he had done, so he
lets the Dark Being inside his heart. Then the main character seals both
of them away.