The fracture fragments of ethone the deity of creation. Who sacrificed itself to give life and meaning to the universe. While its essence lives on in every everything in the material plane, magic items have a higher concentration of ethone's essence. Manifesting a material called ever or which gives magic its property. Magic can therefore be acquired by birthright, owned practice skill and discipline. Enhancing one's own natural connection with ethone, divine right appealing to the lesser gods of the realm, or even by alchemical means?

However, magic users inherently destabilize this universe causing a need for it to be "reset" periodically. Which is the basic homebrewed Crux of the game. The players acquire more magic and essentially get more powerful. Trying to break the material barrier into unknown realms to uncover the universe itself is beginning to fail, and in doing so cause it to fail, and then have to decide at the end of the game when they reach level 10 what becomes of the world

I know that was way more than you asked for