User blog comment:BlackWizardZeref/Fairy Tail: Chapter 436 Memoirs Review with a brief mentioning of Chapter 435 Victory Shout!/@comment-26416024-20150519220151/@comment-83.253.247.186-20150519235320

It seems to me like the stuff with END has been planned ever since the beginning ecause there has been many subbtle hints about it during the series and its possible that Igneel is Zerefs father too.