Idea:
It would be cool if Nyxara would kind of manipulate Anna, then she has a bad mood and give her a temporary succubus tattoo to make her mood better. The first time there would be a special cutscene where Anna can’t take it anymore and fucks you without your consent. After this, if you ask Nyxara to make Anna horny, her mood gets better. And in the early stages of the game you could fuck Anna in this game if you have Nyxara as an NPC in your world, before the 5 heart event.