A Slytherin champion
Surprisingly enough, the school’s not immediately on Potter’s side.
Slytherins obviously hate him (he’s Gryffindor, he’s the boy-who-lived and he ruined the one positive thing that happened to the House of snakes in a very long time)
Ravenclaws despise him, angry for his actions (if for the fact that he cheated or that he figured out how to cheat when they couldn’t, Cassius’ not sure)
And Hufflepuffs dislike him. Plain and simple. Because HUfflepuffs are just. They don’t condone cheating. And they are loyal. And despite what people might think, Slytherins and Hufflepuffs are friends. (Never get on the wrong side of a Hufflepuff, you don’t want to face them when they’re angry)
It also helped that Cedric, their would-be champion, went to congratulate Cassius personally, saying he was sure Cassius deserved the spot.
And then there are the other champions.
Krum, who sits with him during meals, much to Malfoy’s displeasure, and Fleur, who stops to have a chat every time they cross paths.
And Potter, whom no one talks to.
They don’t dislike Potter, but he’s younger (‘too young to be part of this’ thinks Cassius after he sees the heartbroken look in those green eyes when the last Weasley boy sneers at his supposed best friend before walking away) and seems to be on a crusade to be as invisible as possible.
Which suits Cassius just fine.
He’d do it too if it helped him avoid the stinging and tripping jinxes thrown his way in the corridors (always intercepted by his housemates, not because they don’t trust his abilities, but because Slytherins look out for each other and because ‘We want you to focus on winning the Tournament, not on how to avoid petty jinxes from sore losers’ as Estelle had said, kissing him briefly before going to her dorm)
But Cassius’ a Slytherin, and murmured curses and jinxes are at the order of the day when you wear green and silver, so he marches from class to class, surrounded by the safe walls of his housemates and strikes up conversation with any amenable Hufflepuff.
(Diggory is surprisingly pleasant to talk to, and Cassius now has someone other than his teammates to talk about quidditch)
(Neither of the boys were sure as to why they hadn’t been friends before, but Cassius is particularly happy about his new inter-Houses friendship.)
He ignores Malfoy and his posse until that Parkinson girl makes badges, and even then he only walks up to the blond and says that he better include the other champions (‘rightful champions’ is left unsaid)or he’ll feed the badges to the merpeople that always hang around the underwater window of their common room.
If you suggested that he did it because Fleur sighed that it was such a nice idea of his Housemates to make badges supporting their Champion (Cassius doubted she had seen the ‘Potter stinks’ part, but who was he to crush her idea that Slytherins were nice people?) and that she wished her schoolmates could do it too, he’ll deny it to his death bed.
He clearly did it because this whole thing was supposed to strengthen inter house unity and create international ties.
And despite inter house unity having been thrown out of the window ages ago, Cassius was a Slytherin.
He’s smart, resourceful and knows how to play the political game (probably one of the very few stereotypes that people get right about their House).
And maybe when Fleur hugs him because he shows her one of the new badges and he introduces her Estelle saying “This is my girlfriend of almost three years” his smile is a bit wider than usual.
But that’s for him to know.