Gargantua

Gargantua appears in episode two of the anime as a madman, with three bumbling demonic henchmen and a servant named Seiren (derived from the Hellenic Siren). His main goal is to find Eve who is present as the mute, magic-using Jill, assistant caretaker of the orphanage. Gargantua is fiercely attached to her, and accidentally stabs her fatally with a knife when he jealously tries to dislodge a fellow orphan, Ritsuko, from Jill's arms. Jill's body disappears in an explosion of souma, drenching the two children in her life force. In the game, Gargantua and the main character both hold and try to acquire more fragments of Eve. For a while, Gargantua takes over Joe Harry and the command of the "hunters" (smaller, one-eyed hat-looking creatures). (Source: Wikipedia)