For Violet's, you could do some things involving "male in a female body" by possessing the girls, leading into sexual scenes about exploring their bodies and using toys/lesbian sex from their POV.
Something like "possess ai > explore her body/masturbate, use toys, or go to hana and mind control for sex". Or, heck, depending on how you implement it, you could leave "your" body behind to use for sex while in the girl as another option.
This could also lead into some interesting non-sexual plot situations for the story, like trying to stealth or pass as another person for a while.
For the others, though, I've got no clue lol. Only thing I can think of is using Gloria's ability to make toys, but that doesn't seem very interesting.
Just spitballing here though, of course.