Curse of the Shadowmage

Curse of the Shadowmage, by Mark Anthony, is a novel in The Harpers series.

"Long ago, the shadow magic transformed an ancient wizard into a being of utter evil, the Shadowking. Now legendary Harper Caledan Caldorien - heir to the shadow magic - has mysteriously vanished. The Harpers mount a mission to find and destroy...Caledan. But renegade Harper Mari Al-maren and the mage Morhion embark on a desperate quest to rescue him, and stop Caledan before the Shadowking stalks the Realms once more!"