Always napping and constantly sleepy, Belphegor is the second youngest of the vampire brothers but ranked as seventh due to his powers. Belphegor sometimes has a brisk temper, but he's also proactive, efficient, sensible, and mellow. He isn't particularly sociable, but makes an exception for the human, who he likes to cuddle and take naps with. He also lies about the fact that he doesn't like to be pet. He isn't the type to say sorry or accept apologies from others.