Dagon is an oberith, a type of ancient demon that were taken over by the Tinari (the more well known, classic type of demon). May be as old as the creator serpents. Possibly related to the original abberation, otherworldly beings that eat worlds and consume the universe. Dagon is known for destroying the prime material plane once every 722 years and we are due for another cycle of destruction currently, this is known as The World Tide.
Seems to have some beef with The Raven Queen.
Recently chose Varrick as his champion.