User blog comment:IamJakuhoRaikoben/Chapter 468: Memory of the Stars, Review./@comment-26219137-20160110020630/@comment-85.193.154.170-20160110162808

I don't think he will utilise Fire Devil Slayer magic, because he's a demon himself. Why kill his own kind? It should at least be a pyro-Curse (pyro means relating to fire), or he will use his own magic he knows — Fire Dragon Slayer magic. I don't think we'll ever see his Etherious form, since he doesn't know how to transform into it.