At one point, I did have in mind to do one of those stories. I had thought about one of the villainess's followers (you know, they come in a pack) being used as a guinea pig for a summoning ritual. She'd be in the tradition circle, the summoning completes, and a demon possesses the follower. This demon wouldn't quite understand its situation, but, while in the circle, it kept a low profile. The possessed follower would convince the villainess the summoning wasn't successful or, at least, it didn't produce the expected results. Whenever the Academy intro would initiate with the heroine arriving, the demon would sense the rare and high potential of magic in her. That would be the goal: the possessed follower trying to find ways to swap hosts, but the rivalry between the heroine and villainess, the chivalry and (in)convenient timing of romance flags, and the protective charms on areas around the school (mostly to prevent magical violence on the grounds) would always thwart the demon's plans. It's supposed to be a comedy, and I'd love to write it, but I'm also not quite there yet to be in that specific mood for it.