Gradav the Warlock is a level 70 ghostly quest giver and was one of at least three agents of the Violet Eye (along with Wravien the Mage and Kamsis the Conjurer) who were sent to find Medivh's Journal, but were killed in the process. His friendly spirit can be found in the Ivory Tower of Karazhan, in the Deadwind Pass of Azeroth. See Karazhan NPCs