Motives?

So guys, i thought i would ask this here. Much like the game and show, the murders have got to be done with a motive involved. Monokuma normally does something to move the killing along. I would rather not make the same motives like the show, at least not all of them. I was wondering if you guys would like to come up with some that could work?

I thought about one, about Monokuma cutting off the heat to the school, leaving the students to freeze until someone kills someone. But that's about all i got