In this episode, we go to find out what happened at Marisa's house, and get beaten up by a Marisa because that's how all stories go, right!? It's a bit reminiscent of FFIV with Kain, now that I think about it...

No, you're not meant to win this fight at all, hence her 65,535 HP that you see. And why yes, that is an IOSYS reference in her Intel description!