User blog comment:IamJakuhoRaikoben/Chapter 357: The Nine Demon Gates, Review./@comment-112.209.220.215-20131025141330/@comment-7418318-20131025181757

While I like the idea I don't think it's the case. After all he had 400 years of time, but instead of eradicating the other demons, he joined them instead and worked alongside them in Tartaros.