This mob is the Bolvrik (sp?) form of the quest mob that gives the alternate spell quest to Saga Skins. I have also seen the quest giver be a werewolf, named Skald Something-or-other. Didn't seem to matter what form the quest giver was in, it was the same quest, it just seems to depend on what race mobs are up in Svereg at the time.
He is located just inside the stronghold door you are facing when you zone into Svereg. You have to beat the door down just like the one to get in the zone.