A  few years ago DC comics introduced the “meta gene” as the explanation  for some people gaining super abilities under the right conditions.

Marvel has long been based on the mutation principle, whether natural or radiation induced.

I have come to the conclusion that in Qui’ote’s world, magic is the genetic basis for most non technological abilities.

The idea works basically like this.  Several thousand years ago the demi-gods chose to left the physical plane of existence.  At this same time almost all magical/mythical beings left their natural selves in order to peacefully merge with human kind.  Now eons later, as the demi-gods begin to return, their genes have begun to manifest, creating “super-beings”.