User blog comment:FairyRaven/Fairy Tail Chapter 399: Wings of Despair, Review and Commentary/@comment-7418318-20140908095523

I was quite surprised that Mashima pulled Acnologia out already. I fully expected it to be the focus of a following arc and not make an appearance until then.

But now I kinda expect Fairy Tail to fight against E.N.D. on the ground while the Dragon Parents fight against Acnologia in the sky. Of course Acnologia is superious, but the Dragons still manage to hold it off long enough for FT to finish the fight and trigger some Deus Ex Mashima Machina that kills Acnologia or otherwise deals with it (maybe turns it back into a Human?).