User blog comment:SethHeartphilia/Whos stronger Erza or Mirajane/@comment-177.107.9.64-20150913171928/@comment-5268982-20150913175418

Marin defeating Erza was classic Fairy Tail formula with the element of surprise against the protagonists. I'm sure that if she ever meets him again she'll one-shot him to infinity, and then move on to one-shot his Master.