User blog comment:IamJakuhoRaikoben/Chapter 373: Life or Death?, Review./@comment-68.8.113.239-20140301014438

So you know how Natsu couldn't get out of the runes during the fighting festival? What if he's actually from like the past and Layla,(Lucy's mother) opended the eclipse door and Natsu came in, thus losing Igneel. But what if Zeref turned another Natsu into E.N.D and Igneel couldn't fight him because well it's his son! I don't know it's sort of an out there theory