Absorb a spirit and take its energy
Spirit Absorption is the ability to absorb an entire spirit and use their life force as a source of energy or nutrition. The Necromancer used this ability in order to make himself corporeal. The length of time for which he remained corporeal depended on how strong the spirit he absorbed was. The spirit of a Fairy sustained him for a longer period of time than the spirit of a Troll. This power is considered a form of Necromancy.