The Unforsaken Hiero Novel

This is the story of the world after it ended . . .
Five thousand years after the apocalyptic event known as The Death, Per Hiero Desteen - priest, telepath, assassin - has been working to find ancient information to save his people.
The Brotherhood of the Unclean, a roving band of feral raiders, stage an unprecedented attack. They manage to nullify Hiero's telepathic powers, and leave him vulnerable and alone in the wasteland that once was North America.
Now he has to not only survive, but strike back and stop the Brotherhood before they can wipe the vestiges of civilisation from the face of the Earth . . . forever.