Evoker

Evocation is the act of evoking, calling upon, or summoning a spirit, demon, deity or other supernatural agents, in the Western mystery tradition. Conjuration also refers to a summoning, often by the use of a magical spell. The conjuration of the ghosts or spirits of the dead for the purpose of divination is called necromancy. Comparable practices exist in many religions and magical traditions and may employ the use of mind-altering substances with and without uttered word formulas.