User blog comment:IamJakuhoRaikoben/Chapter 468: Memory of the Stars, Review./@comment-5303512-20160113150826/@comment-5303512-20160113192721

@Sane, well Alvarez is calling this war "Ragnarok", so those numberings maybe possible, this also reminds me of my theory of Rangarok.

Acnologia is the Nidhogg, the black dragon who chews on the roots of the world tree.

Natsu is Surt, a fire giant (or demon depending on interpretations) who burns all of the world tree. Depending on the current situation with Natsu if it has anything to do with E.N.D.