One who attempts to divine knowledge (usualy of the future) via communion with the dead. Originally from the Greek manteia 'divination' and nekros 'corpse'. Often refers to any magic aspected to death in works of the fantasy genre.
Demonic conjuration and the delving into the secrets of unlife, the two sides of the skull faced coin. Necromancers, both Hood cursed and deadly.
Why demonic summoning could be considered a branch of necromancy.
The complete comtrol over another life force and the threat of destruction held over it is inherantly death aspected.
- Paraphrasings of the Malazan Book of the Fallen.