User blog comment:LegerPrime/Outcome/@comment-31.205.64.175-20160529191209/@comment-7418318-20160529204502

Regarding the whole matter of Acnologia being scared of E.N.D.... that was just what Mard Geer thought. And considering what we learned of Acno since then I'm inclined to think that Mard was mistaken.

Acnologia himself said he can smell the Dragon Slayers.

When he arrived, there were five Dragon Slayers present (Natsu, Gajeel, Laxus, Sting and Rogue) and Wendy had been there, so her scent would probably still stick around for a bit. So of the 8 living Dragon Slayers we know, only 2 were missing. That's like an all you can eat buffet for someone wanting them all dead.

And to top it off, the Dragons might very well already have been preparing to rise out of their hiding places.

Furthermore Acnologia didn't seem at all interested in going for the book of E.N.D., thus I think that Mard was wide off his mark and the Dragon came for either the Dragon Slayers, the Dragon Parents or all of them together.