Well Happy halloween!
 
3.0 Fluttershy. The Idea is that this happens to her when she doesn’t get milked and too much magic builds up in her that changes her into a succubus.
 
At night she would find her prey and injects her magic through her fangs and pumps her magic into you. Her tongue flexible and long. She can use her tail to give and receive depending on the victim, the inside of her throat has taken a much more vaginal structure for extra pleasure. The amount of pleasure her actual pussy gives might just kill the weak hearted if they weren’t being transformed.
 
Once she has injected enough magic into her victims and has had her way with their enchanted bodies she will return back to her normal 2.0 (or 2.5 state?) without remembering.
 
Thinking this might be a possible way her brother gets changed as they live in the same house. Can imagine he would be the kind of himbo who just openly masturbates infront of his mother and sister at the breakfast table.