Mount Coronet

In the fantasy world I started building with some other authors, and which I've basically been playing with in isolation for a couple years now... there's a similar deal with a limited roster of magical entities. At the formation of the world there were great elemental forces/spirits/gods, and then they were sealed away within the world, and magic is largely dependent on drawing upon their power and the power circulating throughout the world. Besides them, the only supernatural being seen in the world thus far is one that appears in the myths of my constructed culture. Beyond them, all the inhabitants of the world are human. The only thing that makes the people I've come up with special is that one of those forces/spirits/gods is bound to their collective souls in order to keep it from being unleashed.

 

I think keeping a limit on things is a good way to find creative solutions to filling things out. We said "we want magic to be rare, and only humans." I took the other thing we said "magic might be due to primordial gods/spirits/forces sealed within the world" and came up with the idea that one of them might be reverse-possessed by a people-group. Keeps things all-human, in line with the source(s) of magic, and adds to the history of that people.