User blog comment:IamJakuhoRaikoben/Chapter 489: Universe One, Review./@comment-7418318-20160613182830/@comment-7418318-20160613194806

Come to think of it, killing off Natsu could work rather well actually. Zeref brought him back from the dead once, he might be able to do so again.

If Natsu really is dead (regardless of whether he's coming back later) it would be beyond a massive surprise.