[Wolfenstein]

Spoiler:

However, there's also the possibility that instead of doing this to piss people off, it's simply a stunt to re-introduce Kumagawa. At the expense of Emukae's importance and character.

Still horrible either way. Completely breaks the consistancy of the arc so far. Kumagawa was not even supposed to be there, and now you're going to have a fight with the character that literally can't die? Not a good trade-off.

I'd be fine with Emukae losing if it was meaningful and added to her own growth, not just to piss people off or re-introduce a popular character.