The Chaos Balance by L.E. Modesitt Jr.
Paperback. Conditoin: Good+/Very Good-. 1998. Tor.
Book #7 in the Saga of the Recluse.
Nylan, the only man among the matriarchal band of “angels” marooned on the high plateau of Candar. Forced to seek a life elsewhere, Nylan decends into a world of warring kingdoms and strange magics in search of a peaceful life with his wife and infant son. His talents, however, make him a valuable weapon—and so the war between chaos and order begins anew.