Zoufu

Zoufu is a self-possessed shinobi with a skill in swordsmanship equal to Jubei's. He has a monstrous parasite that has lived in his abdomen most, if not all, of his life. He has tried numerous times to kill the beast by coaxing it out by putting his life in danger, as the creature always comes to his aide during battle to preserve its host. His duel with Jubei leads to him finally killing the beast only to realize that its death meant his own as well.