User blog comment:B214/Chapter 504: Rift/@comment-5303512-20161001162856

Since this is an attempted translated chapter, I will only give my thoughts on the current form and wait for MS version to come out.

Well this chapter through me for a loop, I thought it was going to be only Gray vs Natsu fight but it definitely has other things too.

From appearance, it seems that those flames that Natsu is emitting is what is causing some sort of change, like his arms and legs. He lost reasoning but not his memories, so Natsu is angry and hateful, but not in his past self no less, but because he thought that Lucy was dead. It is interesting that that how people thought that other people are dead when their not, but it could be because of Tenrou Island attached to the mainland, though I wasn't sure at first, but now it is most likely the case. And just like with Gray, I doubt that Natsu has not been changed completely.

I also like how this battle is playing out with both sides, making the outcome looking bleak. But most likely to happen is that Juvia and Lucy will come and rescue their hubbies.

From history, Gray wishes to fullfill his father's wishes and family and mentor to kill the Demon that is the pinical of all demons, think of those smaller demons like weeds, pull one up another will eventually take it's place. END is like the greatest of them all, this will be the end of his path, this will be his legacy.

With Natsu, he got like this because that Tumor that turned out to be his Demon Essence was triggered by his rage over the 'death' of Lucy, with both his instinct and hatred, he strives to go kill Zeref, not caring who gets in his way.

when Gray was told out that Natsu was END, he probably doesn't believe until he had to see it, there was some doubt but was not sure yet, when he saw Natsu, he finally got his confirmation, that is when he knew he had to fight. For Gray stopping Natsu, he just had to get Gray out of the way.

With as to who would be responsible Zeref or the Demons, it is like saying who is responsible for accidentally shooting someone, an innocent girl with no knowledge of the existence of firearms and no malicious intent or the gun that shoot.

And onto other parts, it looks like we might either get a Erza vs Eileen or a Mavis vs Eileen. That would be interesting to see, we might finally see the history of Erza!