Ambitious! Daz3D assets of fantasy/sci-fi stuff that actually look good are really hard to find. I certainly wouldn't want to attempt it. (Not that I'm cut out to make Daz3D stuff at all. I attempted to write one of these games making the images in Honey Select, but the amount of work it took to do backgrounds and posing for the mundane scenes that make up 90% of the story turned me off to that real quick, and Honey Select is easy mode compared to a professional toolset. Ultimately it just ended up being a family of character models that I had some fun putting in some naughty poses until I got bored of them.)
A very funny idea, since you're basing it on litrpg web novel garbage, is to make all those stat notification pop-ups for traits and kinks something that actually exists in the world and the MC can react to rather than part of the interface.
Lot of garbage certainly, but I love the idea of them as a long time table top RPG player and game master, I always like a good fantasy or sci-fi universe, but as for all the adult games, there aren't much that satiate me, I find something interesting in a few of them but never enough to say they were the "one", so I always was tempted to write my own too, so why not try with a little cross platform with adult games. ^^
Yes, I understand how such points variables generally work in AVNs.
If you are opposed to having Katherine directly involved in a sex act with Myriam, there are other ways to have Katherine lose her virginity in Myriam's presence (in a more-or-less romantic setting, not rape). Think about it, if the thought appeals to you.
It seems to me that you have already laid the groundwork when you showed Katherine getting excited over seeing Myriam engaged in sex. I've been waiting for another shoe to drop in that thread. Am I waiting in vain?
Of course, I don't expect you to give away your plans. So I understand that you might not want to answer that question.
It's a question I have answered quite a lot of time now, the thing is with Katherine is that she is a very important character in the game and for Myriam, her role being to be always a true loving presence for Myriam, without conditions or doubts, whatever happen one will always be here for the other.
And that imply no corruption, which people seems to keep confusing with no naughty business, there will be some possibilities for naughty moment between Katherine and Myriam via triangular relationships (my plans are with William and/or Jenny). So no, you're not waiting in vain if you want some naughty business with Katherine, but you are if you're waiting for some corruption and humiliation with Katherine, this won't happen.
In the end, each characters are in the game to play a role in Myriam's life and evolution, and Katherine's role is all about love with Myriam, not romantical but still true love, she will always be a positive anchor in Myriam's life in the game.