User blog comment:Kiraofthesky/END/@comment-27019518-20160408204829/@comment-2214433-20160409115204

You're all taking their words too literally...

Zeref is basically saying that it's up to Natsu whether he continues being a human and reaches Zeref like that, or abadons his friends in order to do that, aka being END.

You're saying that "END is within Natsu", but it's been explicitly said that Natsu is END. He gets hurt through the book because that's how Etherious supposedly work, they are Demons created with those books. I'd think of the book as something like Hades' heart, or maybe Voldemort's horcrux for those who are familiar with HP, it's basically a part of Natsu that keeps him alive. Perhaps.

Literally, right now the only way for Natsu to become evil is to "follow the ways of Etherious", aka be drawn towards Zeref in order to kill him since that's what all the Demons have been trying to do and that's what Igneel was afraid of, basically Natsu turning 'bad' because of who he is.

Natsu is supposed to be Zeref's little brother resurrected, it makes no sense for Zeref to give him a second personality/source of power, all he wanted was his little bro coming back. Idk about you, but if I wanted to revive someone I loved, I wouldn't want to see them with horns and a desctructive personality.

He even let Igneel use Natsu for their plan to kill Acnologia, because he hoped that Natsu would become strong enough to kill an immortal, so if there was a demon power within Natsu, why would he bother with having Natsu learn Dragon slayer magic?

Also, as a matter of fact, I'd take everything said about END during Tartaros arc with a grain of salt... Zeref already explained that everything that Mard Geer said about END was a bunch of bullshit in order to bring all the demons together in Tartaros. It kinda screams that Mashima changed his mind, but at this point, everything points towards there not being a secondary power up/transformation/evil END personality. Natsu is END. Simple as that.