The Lord of Shadow Keep

From the back cover: The land lies in the grip of fear. The king is helpless, withered and aged by evil magic. Arkayn Darkrobe, fell Lord of Shadow Keep, rules the country now with necromancy and vile cunning. You are the greatest of the Paladins. You journey through danger and darkness to face the Lord of Shadow Keep. If you cannot overcome his spells and slay him, all is lost! Golden Dragon Fantasy Gamebooks #3