It is clear that there was a problem, mashima boasted END from the village of the sun with the words of atlas flame that:
"" END the strongest and most terrible demon of zeref, that even igneel could not defeat ".
Emphasized in the arc tartaros, which all the arc was intended to awaken END + the words of zeref, Marde and igneel on END and acno:
Zeref:
"" I wonder who will find me first you or him? You will have to choose between the killed or the left to live, you only little to defeat END ""
Marde,:
"" Why is he there? Is it for killing END before its rebirth? the fear it has this point "
Igneel:
"Do not you dare to destroy the book and above all do not open the book under any circumstances, why you are afraid of Acno, the revival of END has been canceled"
And the final revelation of the Arc that natsu = END.
With that alone, it promised us a lot:
-Natsu who was going to become bad because of END.
OR
-End another personality for natsu.
I had thought that if Natsu and END had been separated it was precisely because of this, Natsu had the base was nasty (like goku baby) and was incontrolable, seeing that he had managed to hurt igneel and so was a threat to the plan.
That END is the only demon capable of killing zeref but that by irony it is the only demon that resides at the order of killed zeref unlike the other demon.
So zeref enclosed END in the book and natsu became nice, zeref entrusted natsu a igneel to make it stronger; to take over on END + the plan against acnologia.
Until the day or zeref decide to die for good and then open the book so that END and natsu will make one again.
That with the death of igneel his was going to change something in natsu that would begin to make it sinked in the darkness.
Seeing that natsu asks gray of the finished if he went mad and put himself to the wounded people.
Then with alvarez much thing we changed, Zeref shows us the past that natsu was never bad, that if igneel could not kill natsu it is because he loved it.
But Zeref made a hole in the book, many people thought that END would profit in part to get out of the book and come in natsu.
Which was the case, the seed of the demon is made to grow from the, so it was thought that it was the that natsu would become possessed or go mad or bad.
And had it happened when lucy is "dead", natsu became mad with rage and gets black claws and dimaria describes him as a monster who surpassed the power of the gods and ended up traumatized by it.
And after erza calms natsu and gray and he loses his black claws, we know said he would retrieve them later.
So natsu almost died because of the fusion of the seeds; so it was thought that natsu was going to succeed merged the seeds and become something else.
That the anti-body of igneel would no longer have effect and that it would be transformed into a demon dragon.
natsu wakes up and nothing seems to have changed.
And that's where there was a problem, or that its editor told him not for that.
END died at that time must believe.
Natsu will fight against zeref, he will match, lucy opens the book but nothing happens for natsu, no transformation no PU nothing.
Natsu dies, lucy treats him by rewriting the book, he is cured but nothing more, still no transformation, nor PU.
It beats zeref, the book disappears and natsu survives in a way not very clear.
In what way does the fact that Lucy writes their memory in the book made that natsu is no longer bound to zeref and the book?
Did natsu become 100% human?
Did lucy become the new "" book "" and so is related to natsu?
We know nothing, nothing is said, nothing is explained.
Then he fights acno and still no transformation, nor PU.
And here the manga is finished.
As I said there was so much potential and nothing was done.
Even if it was too late to show another personality for natsu + do an inner fight.
Mashima could make a natsu who goes crazy once the book opened by Lucy but once she starts to rewrite it, natsu gets calm + gets END power, just the black claws.
And in the fight against acno natsu emerges its transformation into etherus full END.
It would have been awesome or even if he had just used the black claws his will have enough for me, history to say that END had a utility for the story.
adding it
