Kouryuu (コウリュウ, Kōryū?, voiced by Hidekatsu Shibata) is a former rival of Ryuken who competed against him for the succession of the Hokuto Shinken. After losing the successorship to Ryuken, he began living an ascetic life in the mountains. Raoh challenges Koryu and defeats him but spares the lives of Koryu's two sons, Zeus and Aus.

Source: Wikipedia