Norse themed necromancer.
Special ability: Raise draugar.
My vision of Hrafnar is that he's a master in necromancy and is able to raise the fallen warriors off the battlefield to fight once again. These reanimated corpses of what were once warriors are popularly called draugr within norse mythology. My idea is that he's around 50 years old, with an early background as community shaman and healer, but also with an uncontrollable curiosity in darker magical crafts of which he became a master later in his life.