Jeffrey (Supernatural)

Jeffrey was a human in Supernatural who loved demons and he always wanted to be one. He was the only human who loved possession. Jeffrey was possessed by a demon who knew of Lilith's location and Sam and Dean tortured him for knowledge on Lilith but the demon escaped before they could get information.

Years later, after Lucifer had been escaped and after the Apocalypse happened, Jeffrey got bored and decided to summon the demon again to become invincible. He wanted possession again and decided to kill women to appease and summon the demon.

Unfortunately, Sam Winchester was being tortured by hallucinations of Lucifer at this point, having been recently freed from Hell, and Lucifer convinced Sam that this world was a mass hallucination. Sam got more evil under Lucifer's influence, and he tracked down Nora, a woman who Jeffrey was going to sacrifice to release his demon friend.

The ritual went right, and the demon was free, but Dean killed Jeffrey and stopped the demon.