User blog comment:Yuri Rozu/Fairy Tail Chapter 506 Broken Bonds(IK LATE!)/@comment-27337151-20161022204537/@comment-5894890-20161023230418

^I can maybe answer that one for you (and Shorya can agree or disagree). Natsu's, or should I say END, has the instinct of killing Zeref drilled into him, so it's natural for him get rid of the things blocking his path (although, it seems he still has some sense of reason). Now, for Gray. What reason does he have to stop Natsu? Because he's associated with the Demon that ruined his family life? (under the alias "demons born from that books of Zeref") Now, that's what I call biased. He's trying to kill one of his best friends because he is known as the most vile, evil, powerful demon or w/e, which he only heard. If anything, Gray should be trying to bring Natsu back to his human self, not whatever nonsense he's doing. Also, if anything, I don't get why Gray isn't helping END get rid of ZEREF, you know, the guy who is the original source of all his tragedies, as well the guy causing this whole war...???