In my fantasy WIP, the MC is just a regular guy (no chosen one or hidden parentage or prophecy involved with him). In the back-story of the world, special abilities and magic was once common. Then the big bad caused a war with Earth and Heaven that nearly destroyed both worlds and since then magic has been greatly reduced to the clergy and some devoted fighters willing to push their bodies to the absolute limit. The MC accidentally stumbles on some kind of macguffin that gives him the same kind of power the Big Bad had back then. And it's enough for the clergy and the government to be interested in him. The problem is I'm not sure what kind of powers to give him that would allow that to be the case. I originally thought of seeing through demon disguises but the clergy would already have that (or some form of it). Then I thought that maybe he could use both the magic based on Earth and the magic used by the Heavens. But then I thought it would make him too powerful and it sounded a bit like Avatar: The Last Airbender or something. So I'm currently stuck. Any suggestions?