I wrote this instead of sleeping so please excuse any weird mistakes-
(Warning: references to plants and beasts from hogwarts legacy😨😨😨😨😭😭😭😭😖😖😖😖😢😢😢😢😰😰😰😰😰😱😱😱😱)
In this AU, none of the characters meet until they become first-years at Hogwarts. If there's any relationship inconsistencies, blame it on that.
Cartman - His favorite class is defense against the dark arts. Mostly because he gets to torture bugs with Crucio. One of his least favorite spells is Avada Kadaver. It's quick and painless, and it doesn't make much sense to him. When he's not in class, which is most of the time, he's messing with centaurs and other innocent creatures in the forbidden forest.
Stan - Despite he and Wendy's houses being considered polar opposites, they hit it off almost immediately. His favorite class is astronomy, and he loves discovering constellations. He almost never uses spells outside of class; he's not used to it. But he's somewhat fond of Accio.
Kyle - He's somewhat of a goody two-shoes, but that's just because he's smarter than most of his class. His favorite class is potions, but he also loves spending time in the library. He and Stan actually met in the library. He and Wendy are kind of rivals for both Stan's affection, and for the highest class scores.
Kenny - If you can't find Kenny, just look in the courtyard. He can usually be found training his army of plants to play pranks on people. He definitely gets the most mail from his parents out of all of his friends. Mostly empty boxes that he's expected to fill with food and return to sender. But sometimes he sends them a Chinese Chomping Cabbage just to tell them to lay off.
Leopold - Butters is almost always in the beasts classroom, cuddling his favorite beasts. He's especially fond of Puffskiens. He's friendly with most of the girls in his house, as well as with Kenny McCormick. They both enjoy herbology, but Butters prefers studying more common, less bite-your-hand-off plants. He gets almost no mail from his parents, but honestly, he's glad. He's scared that he'd get grounded for writing back.
Wendy - The fearless class President, she'll do anything for her friends. She was surprised when she was housed, assuming she'd go straight to Ravenclaw, but knowing how her mind works it's no surprise. Despite what you may hear, she's actually a really sweet girl. Just stay away from her man-
Heidi - Adorably loyal, but extremely gullible. When everyone in class avoided Eric, she tried to be his friend. He accepted this offer, but used her for everything she had. Even to the point of getting her in trouble for the terrible things he did. She's on the brink of expulsion because of him, and there's nothing she can do about it. She doesn't even have a favorite class, because Eric keeps insisting she skips class with him.
Bebe - Wherever Wendy is, Bebe is nearby. She's like a little blonde house elf that thinks Wendy is her master. When she's not following Wendy around, she likes to conjure objects to impress her boyfriend, Clyde. Mostly shoes, not that Clyde cares that much.
Craig - He's very quiet in class, but always ends up getting in trouble anyway. He suspects that Eric uses imperio on him, but he can't be sure. He tries to keep a low profile, but he SOMEHOW managed to get into a friend group. He even has a small crush on one of the boys in it. But he'd never admit it.
Tweek - An oddly named and even odder child, he often spends time in the castle greenhouse growing his own coffee beans. He knows a lot of fire-based spells, such as incendio, so it's best to not startle him, which is next to impossible. Unless you're Craig.
Jimmy - He's pretty much the class-clown. He's always telling jokes, and overall having a positive attitude despite the situation. Most of the kids in his classes like him, and he's the only one able to get Wingardium Leviosa correct, despite his stutter.
Clyde - He's not that bad, despite being a Slytherin, but when his ego's filled, he can be a royal pain in the neck. It doesn't help that he's dating the first girl in class to start to develop. His family's wealthy, and because of that most girls treat him like he's more attractive then he is. Because of this, he gets some of the best grades in the class despite not studying ever or even paying attention in class.
Tolkien - He's very smart, and he's from a wealthy family. It's surprising he doesn't get a big head about it like Clyde does. But he's pretty chill. He'll help you study if you ask, and he'll stand up to Eric when he's getting a little too mean to be joking around.