Martial soul cultivation is a natural part of the soul, but a hundred years ago there was a genius who created an evil art that could consume other peoples' martial soul cultivation. This evil art was called "the martial soul grafting" and he named it "the evil dragon" . The evil dragon's soul is not his own, but that of the other person who took his soul and grafted it into his own. The only way to keep him alive is to kill more people, and that's exactly what the evil dragon is doing. He's killing people so that his evil spirit and his grafted soul will grow even stronger. In other words, the only way for him to stay alive is by killing more people. He says that he once met a teacher from another world, who knew the art of grafting, and he bowed to him and went with him. Then he killed his teacher and slaughtered his own people to take the evil spirit from him. That's the way to become emperor, he says.