User blog comment:IamJakuhoRaikoben/Chapter 452: The Prelude to the Final Battle, Review./@comment-26884814-20150914210434/@comment-24800928-20150918225120

pretty sure turn to dust was like a metaphor or exaggeration but even so his magic immediately kills. One should understand that Zeref is very powerful. Plus, when he has no value for humanity, he can control the power or curse and kill them with an instant. the death magic doesn't only apply when he values humanity.