Sounds good so far and seems to tick the boxes:
1) Slow corruption from innocent girl to a slut
2) Corruption shown by change of clothes, acts done, personality, body modifications
3) Ugly bastard/old man
I just hope that the body modification will not include tattoos and lip augmentation (and if it does, it will be possible to opt out of these interventions on her body).
I would also add live shows/pole dance performances for quite a large closed group of degenerates in some club or abandoned warehouse/basement. There they would vote on what the girl should do (or the pervert who paid the most could decide for himself).
Maybe some BDSM? (bonding, spanking, slapping, whipping, immobilization in strange unnatural positions, electro stimulation, fucking machines)
There's plenty of it on kink.com. I would especially like to see the use of a reciprocating saw, as in this photo in spoiler:
Even a highly corrupeted slut would choose an more attractive partner if she has a choice.
Maybe for money?
Maybe this is the solution? MC discovers that because of men's sick perversions, she can earn money. Big money. The bigger the perversions, the bigger the money. It could be played in such a way that for the clients the girl is a submissive bitch with no inhibitions, but only because of the money.
Let me give you an example: A girl is fucking a client, she moans and groans deliciously, she tells him: "Oh, yes! fuck me harder. I want to feel it deep inside my tight, young pussy." And a moment later, in the next shot, we read what she is thinking at that moment: "God, what a disgusting guy. I don't want him to touch me, let alone have sex with me. If it weren't for the money, I would never agree to it."
However, I prefer the "traditional" path. So MC initially feels disgust, but over time she starts to like it, and after some time she can't and doesn't want to live without it. This approach is more attractive to me.
