Nimue was perhaps the only elf on Sauron's side during the War of the Ring. She had been a follower of Morgoth during the First Age and had taught the Nazgul of black magic during the Second. By the Third Age, she was more powerful than ever. Between them she and Saruman became valued greatly by Sauron for their abilities. She was killed at the Battle of the Morannon by Gandalf the White in an epic duel of magic.