User blog comment:IamJakuhoRaikoben/Sorcerer Magazine, Issue 41: May 2015/@comment-26418194-20150602121708/@comment-25324252-20150605022156

Let me put it like this. Laxus is bigger, stronger and faster than Minerva. He wins in just about every category you compare them in. However, Minerva has two advantages here. The first being that she is a better strategist than Laxus. Minerva can look at the battle conditions and readjust at a moment's notice. The second is that her magic is a direct counter to Laxus' fighting style. Laxus is brutish in combat. He charges in with lightning infused punches. He is mostly a close combat fighter and Minerva's ability move around as she pleases punishes that. Laxus can charge at her but as his attack would land, she could be behind him then rather than right in front of him. Minerva did lose to a severly weakened Erza, but thats simply because it was Erza. For all intents and purposes, Erza cannot lose in battle. She lost her every sense against Kyouka. She should not have been able to stand. It was impossible for her to know if she was standing, if she was moving, if she was facing the right way or even if her attacks connected. She gave a nice speech which should have been impossible because she could not hear if she was saying the right thing. There is a simple rule in the FT Universe, Erza cannot be beaten no matter what. So yes, I completely disregard Minerva losing to Erza because had it been anyone else in Erza's positon, they would have lost. But because it was Erza, she didn't.

Also, we dont exactly know how Minerva's pocket dimensions work. We have no way of knowing if it is possible for someone to escape on their own as everyone thats ever been trapped in it has stayed there until she let them out. So assuming that its not possible to break out, should Minerva trap Laxus in one, game over.