For anyone wanting a slight idea for the newer succubus NTR stuff(v0.50): I will say 4/6 images/scenes are pretty good, and if you want NTR it's pretty classic NTR. Just like with the priestess, each scene is a slight change to the succubus' mentality. What kept annoying me is I figured when she gave you the choice of retiring or not, telling her to stay would leave to the NTR. But like many choices in this game, that one was a red herring. The real deciding factor is when you reach stage 4, is when you see a familiar old man known for plowing your priest girlfriend at the club, you can recommend her to him. If you don't it's imo a pretty good vanilla ending, and honestly I take it over the main ending, or the weird stuff going on with PM.
However, if you do recommend her, you need to start visiting her at the abby the following day, and only during the day to trigger the "after story scenes". Again won't spoil too much, I will say though between how it sours things by the end for succubus' character, and how some of the Iris stuff has gone, I'm not sure if I'm a fan of some of this newer content. Greats scenes in of themselves, but put together, didn't really enjoy the outcome.