Li Chang An, the main protagonist of the show has been sent back into an Ancient World by a booklet with a yellow cover. Here, in this world, with each demon he kills, he would obtain a supernatural power. After he had executed hundreds of thousands of demons, drawn out his sword and looked around him, only then did he just come to the realization that all that he had known, and went through, was just the beginning of a long and drawn – out suffering in this unending hell of demons and death alike.