Comic book series : Fist of the North Star

 Ken is the wielder of the legendary Hokuto Shinken martial arts style and once trained with three other students of the technique. One of them, Jagi, could never accept their Master Ryuken's choice of Ken as the successor. Now Jagi has become a murderous wasteland warlord who terrorizes the innocent...in Ken's name! Ken must face off with Jagi to clear his reputation and the honor of Hokuto Shinken. But Jagi is not the only one of Ken's former brothers who may be using the technique for evil...