That is actually one of my bigger issues with the endings in the HC series. Yes, I understand that the women need to be corrupted, I'm not questioning that. But at the end of the story we have two very antipodal character states, especially in the good and "true" endings. The MC is going to basically be a completely inexperienced virgin in those endings and the female lead is going to be accustomed to sex from a very experienced and more dominant partner. It's particularly bad in HC1 since the villain in that is an immortal demon with centuries of sexual experience and superhuman abilities. In HC2 both main women are willing to fuck around when their partners aren't present. The idea of Casio and Noah being able to satisfy them is laughable. We're in much the same boat with Rose specifically, she's accustomed to sex with a partner who has decades of experience and a staff of maids at his sexual beck and call. In what world could Leto ever hope to satisfy a woman accustomed to that? Even an open relationship wouldn't solve their problems. As much as I might want a happy ending, I just don't think it should be possible.
yes, in the revenge ending of HC2 it is understandable, because More trained Noa for a long time so that he knows how to satisfy a woman, and that in part seemed funny to me given that More was also a Virgin XD, but well they give her justification with her dominant personality and that she is an evil goddess, but in the happy ending they can't simply sell us the idea that Noa could replace Edwryr's place by satisfying Celis's sexual needs, already with everything that she had experienced and the sex she was accustomed to, so the way things are going in HC3 in the happy ending we are going to have an ending similar to that of HC2, where Leto forgives Celis for everything that happened and she comes with Celis's line "to feel better about myself Leto you are free to have sex with other women", being that as you say Leto is a virgin, he has no sexual experience, so it would become somewhat monotonous if you gave us the same ending, unless they give Leto some development in his sexual experience before the end.
What I mean is that it would be interesting if there was corruption on both sides, both on the side of the female characters and the main character, and they could focus more on the corruption of the women and develop the corruption of the male character more slowly.
I say if you can sexually corrupt a pure woman with altruistic thoughts like the ones we have been given in the HC volumes, tell me why you couldn't do the same with a man who is kind and gentle by nature.
But I know someone will tell me that the corruption of women is sexual and that of the male character is mental, but let's be realistic, a purely mental corruption throughout the plot in the main character is not good for a happy ending.