I fear for her sanity if she does so...
One of the reasons I started the Stox Box series was an experiment, to create a character with absolutely no description, everything left to the imagination. If you look carefully, there is no "her" or "him" reference to the victim. Anyone who wants to be that victim can fit right in.
Horror movie is a good analogy. Psycho Sally is intended to be the last character anyone would expect to be the chain saw wielding monster, if she existed in real life. Like any horror movie it's what you know will happen but can't see because it's just out of the camera frame. In the stories the inner Sally becomes more and more visible as a danger, the "she isn't a safe player" you mention, but there's nothing tangible to serve as a warning sign. Just out of the frame we know she's going to inflict great harm, that's her nature, but on camera there's never a visible mark on her victims. Yes, the dark chills are intentional.
Like watching a train wreck or a plane crash there's a certain fascination in seeing the victim's psyche slowly crumble under Sally's relentless onslaught. Adding the bondage, the encasement in the box, experiencing the victim's helpless condition as it contributes to the breakdown, all helps to paint the backdrop, just as the dark basement is de rigueur for the horror movie.
Technical aside: Psycho Sally's description comes from an unexpected source. I'm a big fan of old movies, especially the 1930's B movies. While watching one of the old Nancy Drew series (Bonita Granville played Nancy) it struck me that here was the 30's stereotype of the girl next door, high school student, perky, smart, a solid draw for the movie audience. What if she turned out to be the villain in one of those movies? Hidden behind that lovable exterior she's a soulless psychopath bent on destroying society one person at a time. Psycho Sally is the result.
Jack Peacock