User blog comment:IamJakuhoRaikoben/Chapter 503: The Last Sight Seen, Review./@comment-7418318-20160928235211/@comment-7418318-20160929070829

We haven't seen Natsu use those black flames... but then there never was a need either. Still I doubt that Mashima would leave the God Flames completely dormant only to suddenly pull them out 284 chapters later.