You guys know how there was the whole deal that if dragon slayers developed too much they would themselves become dragons like Acnologia?
Well in the latest chapter 443 there is like this twitch that Natsu gets and it got me thinking what if this is happening to him?!
What if Natsu is becoming the dragon and this is like the final form of E.N.D and this is what Zeref has been waiting for all this time.