Legend Lore: Dagon, formerly Jaqon

Jaqon was a greater devil and former duke who lived on Avernus. Jaqon led his followers in a battle against Asmodeus, becoming an archdevil in the process, though ultimately failing. As retribution, Asmodeus changed Jaqon's name to Dagon, so that if someone tried to summon him, they would instead summon the powerful obyrith instead.