User blog comment:IamJakuhoRaikoben/Chapter 515: I Am You... You Are Me, Review./@comment-117.223.154.228-20161220220753/@comment-7418318-20161221193235

I'm not going anywhere really, I just listed off all meetings with Acnologia we know of... and promptly forgot about Gildarts, which would be at the latest in the same year as Acno's first appearance or probably longer, like 1 or even 2 years... though that's just an estimate. It's amazing enough for Gildarts to survive those injuries, but to recover sufficiently to walk all the way back to Magnolia and get used to his artificial limbs in a few month seems rather unlikely. But at the same time it couldn't have been too many years, since we know he came back to the guild at least twice IIRC after Natsu joined FT, so it couldn't have been the full years.

Either way my point was that it's far easier to explain away why Acnologia didn't come for the DS than it is to explain why he didn't attack Irene at some point due to the timespans involved. 400 years is a lot more than 15 after all.

Just like you I do not thing there's a cycle involved due to the Gildarts and Serena encounters, which would screw any 7 year theories over.

The Zeref involvement theory is still on the table, but with one weakness: Gildarts. When the two met on Zonia we didn't get any hint of Zeref being involved. Of course that's no proof that he wasn't nearby or maybe Gildarts just had the bad luck to stumble too close to Acnologia's nest/roost/hoard/hiding place/whatever and that triggered an out-of-pattern attack, so to say.