A little late to the party here, but my take on Holly and her various endgame routes is a little more tame than others. I agree with the folks who are saying "corruption" isn't the best word to describe what Ivy and Lena do with her sexually and socially if the player chooses that route. "Influence" seems like a better word to me. Same with Ian - his encouragement so far of Holly into some mild kink if Ian is in a relationship with her is also more like "influence" and I think it's telling that the variable Eva is using is the same in both situations.
I'd also note that Ivy and Lena, in the highest amount of influence (so far) still aren't encouraging Holly to be a cheater or get into drugs, or stripping, or Stalkfap, or even smoking - that kind of influence is never even hinted at. What Ivy and Lena are primarily doing are encouraging Holly 1) to be more fit, through the pole dancing classes, 2) to be more sexually active and learn what she likes in sex with both men and women, and 3) be more confident in herself. Now, Ivy being Ivy, #2 means a little light dom/sub roleplay, because that's Ivy's personality. (If she seduces Lena at her apartment this comes out a little bit too.) But as various folks have said in this forum, Ivy seems to have no malicious intent towards Holly, she just thinks that anyone who's her friend would be a cooler person if they were more like her.
With Ian, it's all within the context of a dating relationship, and he's encouraging Holly to be more sexually adventurous and more assertive in bed. Regardless of whether the player has Ian pursue this with her, Holly deeply trusts Ian and feels safe with him as a lover, whether she's being more sexually forward or not.
So, thinking about all of that, my guesses for Holly's endgame are of course some of the ones everyone already knows about: committed with Ian, committed with Lena, or the Holly Trinity throuple. But beyond that, I don't see her turning into a cheater like Gillian under anyone's influence, and I don't see a size queen or QoS ending either. This is ORS, not GGGB. And Holly's underlying personality pretty much stays the same regardless, except where sex and confidence are concerned. Might she have sex with Marcel, as another notch on her belt? Entirely possible. Might she, with no influence at all, and no interest from Ian or Lena, end up alone, or with Clark, or with Stan? Entirely possible, though personally I would do my best to keep her alone than with skeezeballs like Clark or Stan. But it's still a possibility for a Holly who just stays shy and repressed as she is at the start of the story. Here's one for you: after Ivy's influence and going through guys like Mark and Robert, might she end up with
Ivy, assuming a committed IanxLena who are not interested in threesomes? I say it's entirely possible. Or if Ian ends up with someone other than Lena, could there be HollyxIvyxLena in the end? Again I think that's really possible. They could all live in Ivy's apartment, and Ivy and Lena can make Stalkfap content, while Holly writes her next book - and does camera work and tech support.
I guess my overall point is that while there are various endgame options for Holly (and likely more of them than for any other secondary character), I think Holly's options are limited - in a good way - by her underlying character, regardless of the influence, which is not corruption, Ivy or Lena or Ian have with her.
You can all tell me I'm wrong now, and describe in detail the gangbang and bukkake waiting for Holly in the basement of Blazer with Marcel and all of his friends, with both Ian and Lena watching in shock from separate corners of the room.