User blog comment:IamJakuhoRaikoben/Sorcerer Magazine, Issue 41: May 2015/@comment-25111584-20150602132552/@comment-25111584-20150602140956

Nah, I'm just saying that Laxus is just strong enough to break through those bubbles.

To get technical, Minerva seems to have walls separating the dimensions. She obviously has to maintain them and can manipulate them. Laxus just has to break those. Given the difference in their power levels, he should be able to do so with ease, unlike Erza and Kagura.

The argument that the dimensional walls cannot be harmed is made weaker (though not refuted) by how Natsu was able to negate Genesis Zero. Minerva's Territory Magic actually seems more tangible than GZ.

Essays are torture! They are the spawns of denizens of the infernal pits, conceived only to make students fall into despair! I'm talking about the kind of essays given as homework tho, not the ones we sometimes write in blog comments. :P