Asmodeus

Asmodeus was the rule of the nine hells, as well as over the ninth specifically. He was also the holder of contracts for most tieflings who were born. 
== Biography ==
=== History ===
During the Blood War, in which celestials fought with fiends, Asmodeus set in motion a plan to become a resident of the material plane in addition to hell. This residency would grant him the ability to begin a true conquest of the material plane. To these ends, he had his physical form divided up and sent to the material plane, where it would then be reassembled and he would be "born." 
Around 887 A.C., his primary follower and high priest, Caius attempted a ritual to revive Asmodeus. He intended to use a tiefling of direct decent from one of the original tieflings as a vessel for him to enter. Unfortunately, the ritual was only partially successful, with a portion of Asmodeus entering Caius instead of the tiefling, and causing that particular option to no longer be viable. 
=== Campaign One ===
The pieces of Asmodeus' body had been transformed into magical items known as the Icons of Sin. These items were pursued by Caius as once his previous attempt had failed. As a result of his work, the items were indeed collected, though not by him. Belxari and Sah, having been tricked by Caius into gathering them, had realized what they were and worked to destroy them. In the act of destroying them, Asmodeus was again partially summoned on the material plane. He was, however, defeated before he could obtain his Icons to try again. 
=== Campaign Two ===
With Asmodeus returned to hell, he had to work his way back to power once again. His nephew, Malkaziid, was vying for control of hell, resulting in a civil war which caught the attention of the celestial forces and gods. A group of mercenaries and followers of Quraura and Bahamut—as well as [{Xelbari]], who mostly just tagged along for the fun of it—were sent in to attempt to broker peace. They were ultimately successful, siding with Malkaziid and defeating Asmodeus in combat. Upon his defeat, from his body erupted a giant raven-like creature. Xelbari recognized this as Caius, and destroyed the creature. He then made a deal with Malkaziid to take on the tiefling contracts from Asmodeus, thus becoming effectively his successor.