Hokuto Shinken
Kenshiro ends up encountering numerous rival martial artists, including the six grandmasters of "Nanto Seiken", a rival assassin's art, as well as his own adoptive brothers who competed with him for the "Hokuto Shinken" succession. Kenshiro's ultimate nemesis ends up becoming his eldest brother-in-training Raoh, a warrior who broke the law of "Hokuto Shinken" by killing his master Ryuken and refusing to surrender the succession to Kenshiro. Raoh seeks to conquer the post-apocalyptic world as a warlord under the mantle of "Ken-oh", the King of the Fist, by challenging every martial artist he sees as a threat. After a long series of battles, Kenshiro emerges victorious over Raoh and it seems peace has finally come to the post-apocalyptic world, concluding the first half of the story.