Lucius's sin is the deuteragonist and an anti-hero in the Phantom Paradise series. He is a demon who desires to devour countless souls. He tricked Lucius to use him as food but Lucius's childhood friend, Hayate made a deal with him. In exchange for saving Lucius's life, the demon demanded Hayate to give him the soul of Empress Madonna.
He wears a white fluff around his neck and wears no shirt. He instead wears two belts around his chest.
He is harsh and likes to taunt Hayate. As time goes on he starts to take a personality closer to Lucius. It is learned that if Lucius's sin doesn't eat souls then he starts to become one with Lucius.