Thanks for the report! Let's take a look here:
-On checking, this doesn't look universal (not seeing it on my saves in those areas), which means something specific to your playthrough caused it. The question is, what in particular? I have no idea what might be triggering that, but for now I've added cleanup code to the post-battle eval so Mezz's battle sprite should be reset to normal, either clipped or not as appropriate. Will be in with a bunch of other fixes when the next release eventually happens.
-So when Mezz cums, it can either just inflict damage, or (with the mashers) push him forward to downed state (kneeling). In either case, the hypno effect should stick around until he picks himself up. Are you saying he came and knocked himself all the way back to normal, but the mist and commands from the downed state remained? I took a look at the relevant code, and did see a few things that weren't matching, so some minor tweaks have been made. Hopefully that catches the bug.
-The downed/Guuuh state is intended to simulate Mezz attempting to recover while there's a lull in the fucking. The whole idea is that the boars aren't paying close attention to him, so additional dialogue/taunts wouldn't make sense. That said, going right back into fucking if he fails say 3 times might make it more interesting/raise the stakes a little, and help with flow/speed. Will consider.
-HP in the game has to serve as a metaphor for a lot of things, because it's not worth having half a dozen gauges. Rather than strictly "health", it's more like "ability to keep fighting". It's also leveraged as a carrot and stick: you'll do what increases it, and avoid what decreases it (unless you're trying to get event CG). This fits with the overall situation, which is that the clips are "training" Mezz. As such, being good and doing as you're told is rewarded with "HP" and energy, whereas resisting costs energy. Cumming "costs" "HP" because you're supposed to prioritize the boar's pleasure over your own, and because them getting an orgasm out of you is a little defeat. Think of it like successfully landed hit.
Or maybe it makes more sense to think of the battle system as two battle systems that hand off between themselves. The first is a traditional one: both sides inflict damage, and the one that runs out of HP first loses. The second is pleasure-based: both sides inflict pleasure, and the one that runs out of "HP" first loses (note that the boars leave once they're "satisfied," and Mezz can "win" this way.) Obviously what HP is technically changes during the handoff, but you have to forgive an imperfect metaphor.