King Beyond the Gate by David Gemmell (The Drenai Saga, #2)

A century has passed since the heroic defence of Dros Delnoch. But the people of the Drenai face a new terror: a mad emperor kept in power by two forces of unsurpassed evil. The Joinings are werebeasts of awesome power. The Dark Templars are warrior-priests whose fighting skills are without equal. Against them, the Drenai face certain defeat.

One man, an outsider hated by the Drenai for his Nadir blood, and despised by the Nadir for his Drenai ancestry, sets out to bring down the emperor. He is one man against the armies of chaos.

He is Tenaka Khan - the Prince of Shadows.

Book by author David Gemmell.