Gideon's Dawn by Michael D. Warden

The Inherited Lands were a place of legend--a mystic realm in a world rich in miracles. From here, Life flowed to the four corners of creation. Or so it once was, before High Lord Gideon used a Word of Desolation that Abaddon had taught him, unleashing a corrupting perversion. Two thousand years later, another Gideon has appeared. No one knows where he came from or how he arrived. But they know he has power. This is no ordinary sojourner, they whisper. This may be the answer to ancient prophesies of doom and deliverance. Or he may just be Gideon Dawning, a graduate student from Texas, in over his head in a world beyond time. . . .