Asmodeus

Lord of the Nine Hells, and the first devil

The First Prince of the Nine Hells, the Possessor of Throne and the Guardian of the Pit: Asmodeus, the strongest and most feared devil to ever grace the planes. With powers equal to those of the Celestial Gods, Asmodeus was granted sovereignty over the entire plane of the Nine Hells at the end of the age of Silence, when he had distinguished himself from the hordes of demons as a singular being: the first devil. Said to be a colossal muscled giant whose face is obscured by a choking cloud of ash and smoke, Asmodeus rules the Hells from the Throne, the second-deepest layer of the plane and the gateway to the Pit. He is the only creature to occupy the Throne. It is said those who try to meet with Asmodeus without taking proper precautions are instantly vaporized by the sheer presence of the first devil.
The Throne itself is a massive floating disc of obsidian, jagged and superheated beyond mortal tolerance. Asmodeus rarely even communicates with his arch-devils, and is known to have a terrible temper when riled. The last devil prince to anger him, Lolth, was said to have been pulled apart limb from limb and thrown into the Pit. The other devil princes make an effort to appease him, for all their power none of them can match him. The only rival in power Asmodeus has is Tempus, who took control of the sin of Violence after being cast out of the Material Plane by The Godbreaker. The two have a tenuous peace, for now, kept at bay only by the mediating presence of Sune in the Palace of Flame.
Asmodeus has a legendary weapon, a blade of molten rock called Judgement, and his crown is said to grant dominion over his powers. The only catch is, with his face obscured by smoke, no one has ever seen his crown, with the exception of the vague suggestion of horns. Some scholars suggest that the crown does not exist, and the legend implies that one must kill Asmodeus, or "take his horns", to become Prince of the Nine Hells. It is said that Ralishaz, god of madness, is the only being who has seen Asmodeus's face.