User blog comment:IamJakuhoRaikoben/Chapters 338, 339, 340: The Great Banquet, The Stardust Essence, & Gift, Review./@comment-5036235-20130706004343/@comment-7418318-20130706080947

You do know that you can edit your posts right? There's really no need for a tripple post....

Mavis can't do much of anything, because she's just a ghost. She was able to use the magic power and believe of the living FT mages to create Fairy Sphere, but by herself she can't do much more than making other people feel uncomfortable with her ghostly aura.

As for Zeref: Why would he stop Acnologia from destroying the world when he himself also wants to destroy the world?