Alright, you're probably not going to get anything new, so I only have a SFW suggestion that I'm playing through myself now. Star Wars The Old Republic. You can play a female Jedi Knight and play out a corruption arc. It's got a ruthless Sith love interest, gradual corruption through dialogue and plot choices, the option to betray and sabotage your own faction, and visual / clothing transformation (there is equipment specific to Dark Side characters). The only thing it doesn't have is on-screen fucking. You will need to pay for at least a month of subscription (it's unlocked forever after that) and probably play the game for hundreds of hours to see most of it (which I haven't yet), so the suggestion is purely for Slaaneshi degenerates like me.
