User blog comment:Wrath022/Chapter 516: The Truth About Enchantment, Review/@comment-24784846-20161227035636

Well, I'm not sure if it's "convenient" per say. Irene made herself weaker, but would Erza actually attack Wendy? Can Wendy even be saved? The fight gets more difficult if Erza refuses to attack Irene in Wendy's body.

Perhaps it's just my opinion, but Irene's own obsession being the reason she lost is fine by me. I'd be even more bs if Erza and Wendy beat Irene in a competition of power.