User blog comment:Miskos3/Fairy Tail 535: The Greatest Power, Review/@comment-5708675-20170512170508/@comment-7418318-20170514082448

"Can't blame em tbh there's basicly no-one left who'll willingly fight this insane dragon since they're either occupied or scared."

There also a more basic problem than that. No one else of the present people can fly. Any kind of magic they might be able to launch at Acnologia would not only be ineffective, but since he can eat it would even strengthen Acnologia even more.

They are literally helpless. The best they may be able to do is trying to distract Acno, but even that is unlikely, since he can just ignore them and be fine anyway.