Myrkul

Myrkul is the God of Death in the Forgotten Realms setting of Dungeons and Dragons.

Myrkul was originally a mortal prince, who became a necromancer and joined a group of epic level adventurers called the Dead Three, alongside the tyrant Bane and the assasin Bhaal. The threes goal was to gain godhood by slaying the the former god of Strife, Death, and the Dead, Jergal. After reaching him however, he revealed that he had guided them all along to him, having gotten tired of his position. After a game of knucklebones, each took a third of Jergal's portfolio, with Myrkul claiming the portfolio of the Dead. Jergal also became a mentor to Myrkul, wanting to instruct and advise him in his new position.

Myrkul was thought to have died during The Time of Troubles and been succeeded by Kelemvor, but had actually been residing in an artifact called the Crown of Horns, corrupting any who found it to worshipping him. He eventually regained his godhood during the Sundering.

He was also behind the events of Neverwinter Nights 2: Mask of the Betrayer, where you could also kill him ; peacefully by sending his essence on in peace or violently by absorbing him into your spirit eating curse. Doing the latter would eventually turn your character into a plane-hopping, god-eating abomination.