If you wake up in a field of green grass, looking at a woman of flesh and steel. Be glad, you are dead. If you wake up covered in blood and shit, be gladder still. For you are alive and your time is not yet come!
Cowardly maggots! Bow your thrice cursed heads and thank the goddess that you still draw unworthy breath!
All spell casters gain their abilities through a form of demon possession. So in order to gain magical abilites, PCs must track down and trap demons. Of course there are some pretty powerful demons, if the demon is stronger than the PC, the PC could find themselves subjugated to the Demon's will.