A preface to something…

What are demons to your game world?

1. Representatives of an absolute, objective evil (Hellblazer)
2. Ancient races who walked the earth aeons ago (Buffy)
3. Extra-planar beings separated from our world by a metaphysical barrier (Moorcock/Stormbringer)
4. A breach in consensus reality (Sorcerer)
5. A manifestation of personal power or psyche (also Sorcerer, early Stormbringer RPG)

That list moves from objective to subjective; in the middle point you get some kind of hand-waving “other dimensions, too numerous to count, fluid reality” explanation.

Consider two axes — on one you move between an objective and consensus reality to a subjective one, and on the other you move between summoning (and bargaining with) something other to conjuring something from the self. For example:

Until next time.