User blog comment:JohnnyN64/END/Natsu theories don't add up/@comment-97.112.55.109-20150325175650

Theory:

Could It be that END is another personality/spirit that is a part of Natsu? Zeref shows that he has knowledge of the future, and he says a few time that Natsu and he are meant to fight, so he could have prepared that book in anticipation to meeting Natsu to ensure that he (Zerfe would lose), or if anyone has read the Pandora Hearts series, I wonder if Natsu has a similar case to Oz? (he's body changes or has changed?)