Got some idea.
1. Mentor can leave some trace on Aster after thier interaction.
(Such as lip print or hand print or hair or somekind of liquid)
2. Mentor can equip Aster with something naughty, some of them are
permanent
3. Some thing like rubber appears in shop, the best is Aster tell MC to buy it, and MC Have no idea what will going on.
(None protection may cause some consequence, can affect ending）
4. Want nightvision potion or whatever can let me see Aster in low torchlight, of course it won't stop anything, just want to enjoy it properly.
5. Love lever so we can see how Aster fall from us to Mentor.
I'm not professional, just put forward my idea. Your game is amazing, good luck with your development.
: )