Halldir

Halldir is a ghost and mage, possibly also a Draugr, encountered in Halldir's Cairn. He can multiplicate himself. These three copies use ice, fire and lightning spells. After they all three have been killed, Halldir spawns back in the middle of the room, so Dragonborn can finish him off.

Quests

 * Find Rjorn's Drum
 * Find Runils Journal