|Name in Japanese||ベルフェゴール|
|Nickname(s)|| Alternative Ayumu|
|Voice Actor (Japanese)||Junji Majima|
|Voice Actor (English)||Austin Tindle|
|Age||16 (As Ayumu)|
|Classification||Seven Deadly Sins|
|Debut (Anime)||Episode 10 (Season 2)|
Belphegor (ベルフェゴール, Berufegōru?) is the Demon Lord of Sloth and the representative of Ayumu's strongest sin, laziness. He is in Ayumu's memories when Ariel erases most of his memory and they enter his head.
Belphegor looks just exactly Ayumu, though he wears his clothing more loosely by keeping his white shirt unbuttoned. He also wears a Rosary around his neck.
Belphegor is crude, arrogant, chauvinistic and generally apathetic. In terms of personality, he is the exact opposite of Ayumu. He is also quite lazy, as befitting his title, but completely self-assured in his power. He is guarded by a couple of the other sins that he calls them "bouncers" as if they were body guards. Belphegor is the strongest of his deadly sins, and considers himself "the real Ayumu" or "Ayumu's real self".