Hell is supposedly divided into various levels or layers. Wethere these are actrually geographical locations or merely manifestations of concepts is unlear and perhaps best not researched too closely.
It is also assumed that each layer is ruled by someone. In this case the 4th layer is ruled by a Lord. He is a classic Devil with a goat's head, cloven hooves and a tail. Large bat wings adorn his back and he is clad in armour of infernal design.
He is a warrior rather than an intellectual and has been seen with four arms, each wielding a different weapon.
Note: DevilMother and DevilSon are not from the Fourth Layer.