Koryu was an evil auspice that opted to embrace their animalistic instincts and terrorized the world. Koryu faced Tenzen and the Four Lords. Due to Koryu's great power, Tenzen sacrificed himself to seal Koryu in Reisen Temple.
Over the years the seal has weakened. Genbu, with the help of the Warrior of Light, reunited the Four Lords to prevent Koryu's return. Koryu manages to break free and faces the Four Lords once more. During the confrontation, Tenzen's spirit appears to help the Warrior of Light and the Four Lords seal Koryu again.
Kōryū (黄竜, read also as Ōryū) means "yellow dragon" in Japanese.