SOLVED. YA recent Dystopian novel. Contestants forced to kill each other for TV (NOT hunger games). [s]

[Amelia]

I read this probably 2018-2019, and it had been recently released. The cover showed 4(I think) people, drawn in the style of the bathroom people(very basic shapes). One of the people was beheaded. In this world, people were forced onto an island or something(maybe alcatraz), where they had to kill each other and avoid being killed. The main characters formed a group, and they referred to themselves like the Breakfast Club, but they were the Breakfast Club of murders, or something like that. The main characters name might have started with a 'C', and I think she had a sister. It had a sequel, and I think the cover of that was bright green. In that one, I vaguely remember a scene where they were in an abandoned factory or warehouse thing and it was very bloody.

[Ashley]

#Murdertrending?

[Amelia]

Yes, that's it! Thank you!!

[Ashley]

You’re welcome =)