User blog comment:EvanDude345rv5/Fairy Tail 356: Tartarus Arc Prologue/@comment-82.20.156.238-20131020170057/@comment-7418318-20131020180516

I never intended to imply that Fairy Tail did not defeat it, just that they didn't kill/destroy it.

Just like they defeated Hades, but it was who Zeref landing the killing blow later.

Of course they shouldn't just leave a greater demon (or however you want to call it) lying around and go off to celebrate, but maybe it somehow manages to slip away from them after the defeat, vowing to come back for revenge later, just to end up annihilated by Zeref, because he's pissed off about it's failure to complete it's objective.