I’m sure it’s an accurate translation but man does it bother me that it says “my name is Belphegor, the demon of lust and greed.” Typically, Mammon is associated as greed, and Asmodeus with lust. Belphegor is the demon associated with the sin of sloth.
Granblue like to borrow names of, heroes, gods and demons but change their story and lore to fit the in game universe. The primal beast can be considered FF summons and this enemy in particulary was invented for the idolmaster collab.