What if the Connecticut Yankee In King Arthur's Court was a real wizard?
Alexan is exiled from his home for reasons of politics and health, sent to a primitive locale to guard against the misuse of the massive power coursing through the fabric of reality. He discovers that he is what the locals call a wizard. Unfortunately for him, there are many other wizards and even gods connected to this power, and they tend to be unfriendly to those they fear might rival or replace them – people such as Alexan.
And what about this demigoddess that keeps popping up with obscure hints about her divine curse?