Dragon's winter

Twin boys were born to the dragon king of Ippa, though only one was born of dragon blood. He was named Karadum Atani, but he would never become a dragon. In a bitter betrayal, his twin brother stole his talisman and disappeared, leaving Karadum trapped - a king with the heart of a dragon, imprisoned in the body of an ordinary man. Now, years later, rumors of evil sorcery have reached Dragon Keep. A powerful wizard has risen out of legend. Some call him Ankoku, the Hollow One. But Karadur knows him as brother. Beneath the dragon banner, Karadur leads his warriors into the ice to challenge his wizard brother and reclaim his destiny.