Tian Hei Long (田黑龍), the final and most powerful antagonist of KO One, is the evil twin brother of Duan Chang Ren and the leader of the Martial Arts Syndicate (武力裁决所); a group that was created by him and six other people, two of which being Duan Chang Ren and Wang Tu Long. In the initial years, he dreamed to take over the world, and that dream drove him mad. He killed most of his teammates. Duan Chang Ren managed to save himself by stripping away his own powers.