User blog comment:IamJakuhoRaikoben/Chapter 497: The Winter Mage, Review./@comment-24951162-20160810202218/@comment-2214433-20160815212125

That's because the book is directly connected to Natsu, literally being Natsu. When Zeref damaged the book, it also hurt Natsu. If the book is destroyed, Natsu will most likely die, after all, Zeref just had to burn Mard Geer as a book to destroy him.

All the other statements have either been proven false or they were metaphors/characters playing along. Both Tartaros and Fairy Tail believed they were fighting for/against the revival of END and clearly, nor Igneel neither Zeref were gonna reveal the truth at that moment, so all they provided were cryptic statements. Or Mashima/the editor simply changed their mind over the time.

The battle of Natsu against Zeref clearly reveals that Tartaros arc is full of bullshit as far as statements about END go. Mard Geer is basically called a liar and Natsu's past is revealed as follows:


 * Natsu dies to dragons.
 * Natsu is eventually revived through Etherious means. Please read chapter 436 and notice that Natsu is no longer called 'the strongest', but rather Zeref's final work, a revival of his little brother, a human.
 * Zeref meets Igneel, learns of his plans of defeating Acnologia and agrees with Natsu taking a part, but not because he gives a shit about Acno, but because he hopes that Natsu will become strong enough to kill Zeref, the immortal.
 * So Natsu spends his time with Igneel and we know that at one point, Igneel thinks of killing him - wouldn't you also, knowing that he was Zeref's creation? - but is unable to because he ends up loving Natsu.
 * Eventually, after enough training, Natsu travels to 400 years ago, with Igneel seemingly disappearing. We know what happened. Natsu then joins Fairy Tail and the rest is known.

So we know that


 * Natsu didn't create curses
 * Natsu didn't create Tartaros
 * Natsu wasn't evil before, nor was he shown displaying any 'evil' qualities.

All of the above, as well as END being the strongest demon was spread by Mard Geer. And Mard Geer was a liar.

If, in spite of all these implications and other hints, Natsu still ends up having a "demon transformation", it will be the most contradicting thing in all of animanga and as far as Fairy Tail goes, Erza vs. Kyoka will seem Nobel Prize-worthy compared to the bullshit that Natsu's "other form" would be. I just don't understand why Mashima would go through the trouble of denying half of Tartaros arc's information about Zeref and Natsu, if he was gonna say "fuck it" and go yolo with Natsu's that-shouldn't-exist evil form.

Also, why is this thread still going on?