Death
The entity: Usually, this implies a superhuman being who generally dwells on an extra-dimensional world and who has at least temporary control of certain ghosts. These beings are sometimes physical and sometimes ectoplasmic. The most famous gods of Death include Hela, Mephisto, and Pluto. There is actually a quasiphysical ectoplasmic being known as Death that embodies the same, but she shall ignore most entreaties.
The spells: Any spells that one of the death gods might grant would have to work for them, that is, accomplish something they desire. Since this usually is the death of a character that is hard to destroy (they seem to yearn more for those they cannot easily have), the decision to entreat a death god is one with dire consequences, including total Karma loss(Judge's discretion).