The Book of Seth — Michael Orona

The Black Nether novel series is the story of Seth: a man tormented by anguish, and an empty shell of a person. He had lived a lie for too long, forgetting who he was, and trying to live up to an image he could not maintain. As his life became an endless nightmare of loneliness, Seth enters a portal, or rift, and is sent into a fantastical world called Aevum, manifested through the raw stuff of creation called black nether, driven by his torn emotions. An alternate reality, Seth must battle against a growing religion that is extending its might across a world torn apart by centuries of civil war. Though he discovers strength and power in the strange reality by manipulating the black nether, a shadow stalks him, waiting for their inevitable meeting in which Seth must die.