The sin war - Richard A. Knaak

Three thousand years before the darkening of Tristram, Uldyssian, son of Diomedes, was a simple farmer from the village of Seram. Content with his quiet, idyllic life, Uldyssian is shocked as dark events rapidly unfold around him. Mistakenly blamed for the grizzly murders of two travelling missionaries, Uldyssian is forced to flee his homeland and set out on a perilous quest to redeem his good name. To his horror, he has begun to manifest strange new powers, powers no mortal man has ever dreamed of. Now, Uldyssian must grapple with the energies building within him -- lest they consume the last vestiges of his humanity.