Sorry, looks like my wall of text ended up being confusing. A picture is better than a thousand words.
Steps to reproduce:
- Win in less than 3 matches and/or faster than 10 seconds, without any companion to make sure the companion won't affect the situation. You WILL require a lot of luck and extremely quick reflexes unless you are hacking.
- This only affects enemies that can be beaten extremely fast. Late bosses, regardless of the tile matchup, should not be an issue as it is impossible to reproduce this unless the entire screen is clearable in one go.
- Line does not have to wear specific gear. I can reproduce it with her not naked, so that isn't a factor; she did not take any damage either, and being damaged while not clothed AND not winning too fast works properly ("cloths %" will be properly calculated) so that is not a factor either.
This isn't a game-breaking bug and I understand your concern about farming, but the arc output in there really is minimal, so just making sure this isn't a "problem".