Raizen (雷禅, Raizen) was part of a special type of elite and powerful demon called a Mazoku (loosely meaning the "Tribe of Devils", translated as Demonkin in FUNimation's subtitles of the original japanese anime.). He was also one of The Three Kings of Makai and Yusuke Urameshi's ancestral father. In the anime, prior to Yusuke's departure to demon world, Raizen is called Toshin by Hokushin. As this can be translated to mean Battle God, it is likely a nickname rather than a surname. He is also called the Master of War or Warrior God depending on the translation.