The majority of my fantasies revolve around keeping the victim in long term captivity and one idea I've had is placing her in a straitjacket, and then hooding and gagging her before taking her out to a fetish club and leading her around on a leash and collar, introducing her to friends as my new slave and privately savoring the irony that I mean it literally.
So, the victim's now in an environment where it's totally normal to look like that and also completely unable to communicate to anyone that her situation is not normal at all (possibly some mild drugging first to make sure they can't cause a scene but are still fully aware).
Eventually, I tell my friends that it's her birthday and in honor of it, I'm going to help her fulfill her longtime fantasy of getting publicly gang banged, and then proceed to strap her down to one of the pieces of bondage furniture with her legs forcibly spread. Then the fun commences and keeps going until absolutely anyone who wants a turn has had one.