User blog comment:FairyRaven/Fairy Tail Chapter 435 & 436: The Cry of Victory & Memoirs, Review and Commentary/@comment-115.241.39.191-20150518150526

We already knew Natsu is 400+ years.My intial guess is Zeref created/restored E.N.D and also happened to have created/restored other demons[now known as Dragon slayers]. Dragons must have learned about this and happen to adopt and teach them Dragon Slayer Magic.That explains how Natsu and Gajeel were trapped under barrier during Laxus invasion.

I kinda loved how Natsu is the reason for Zeref' s actions[evil doings].

Chapter 436:10/10.