User blog comment:Wrath022/Chapter 517: Wendy Belserion, Review/@comment-24489996-20170117142631/@comment-24489996-20170117154537

Again, I didn't write this; it just came from a tumblr I just happened to be looking through at the time. But I do see your point in that, so there's no clear distinction of Minerva being more powerful than Erza in that regard.