Baatezu

The devils, of which the ruling type are called baatezu, are lawful evil natives of the Nine Hells of Baator; they subjugate the weak and rule tyrannically over their domains. Pit fiends are the most powerful baatezu, though even the strongest pit fiends are surpassed by the Lords of the Nine, or Archdevils, whose ranks include Baalzebul, Mephistopheles and Asmodeus. Unlike the demons, the devils arranged themselves through a strict hierarchy. Like the demons, the devils are scheming backstabbers; while a demon only keeps its words when it is convenient, a devil keeps its word all too well; though being used to exploit repressive bureaucratic machinations to the fullest, always knows ways around the letter of a contract to begin with.