These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Being sent from an all ghouls school to another school where the magical and supernatural are commonplace doesn't seem too odd on paper. At least not until you realize that the headmaster of Charybdis Heights probably knew the nature of Artemis Academy to begin with. Meaning the headmaster knowingly sent three witches to a school for monster hunters. With another school next door that probably specializes in the same thing.
Artemis Academy, as well as Apollo Academy, are named after pagan gods, and their students hunt monsters, and other supernatural beings.
Explained at the beginning of chapter ten: they have been sent undercover,
Magnificent Bitch: Putting Tiffany on the spot about having to break her brother's arm, as per the school's protocol, then letting her off the hook, to spare him, while making herself look good at the same time, was pretty clever.
Moral Event Horizon: Cerise exposing Mel and Jacqui as witches when they're surrounded by Artemis Academy students. While it can be justified as resent towards Melissa, Jacqui did nothing to Cerise that would earn Cerise's spite. Had Faith not grown to trust Melissa, it's very likely the two of them would have been eliminated, or at the very least captured. And given she's shown to be completely aware of her actions on the following pages, she did it with no dark influence whatsoever. Even worse, recent strips reveal that the transportation circle Cerise trapped everyone in was meant to dump everyone into a volcano.
Even worse, one of the people in the student council and caught in the teleportation circle was Callista, you know, Cerise's girlfriend? And Cerise has currently hooked up with Skye, that's right, she's not only a cheater but has gone so far as to send her girlfriend to her death without so much as a telling her she was breaking up with her!
And she tops that by gleefully gloating about it to Melissa without a shred of remorse.