So, while I was going for rework of main quest line, which will generally focus on getting player into game mechanics, I discovered that we need an actual penalty to overuse of fun stuff, like potions (and maybe spells, but that is to come). So now there's a toxicity. Stuffing your servant with potions or dubious medical procedures will result in magic toxicity build up.
Toxicity will slowly dissipate as time passes, but with overuse it will cause negative effects, like health, stress issues, willpower damage and mutations. For mutations I wrote whole new script which I'll surely try to use in some other places. Basically it will roll the dice and depending on outcome will change one of the girl's aspects, be it something small, like hair color, or something big, like growing a cock, or few more tits.
This will likely be main penalty (or reward, if you are into it) for various experiments and actions related to fooling with magic. As a side note, I do want to add more purely monstergirl-esque races in few next updates. Stuff like lamias, scyllas, insects, maybe even slimes. Although it's a bit of question how they gonna function, but probably mutation list will also expand.