(I would say Karma, but I feel like it would be more than obvious when it comes down to him X3, What if either or both Curii and/or Ren? I also think the role would be pretty well fitting for maybe Kayano and Maehara :3 )
Karma Akabane
Karma did as he was told. Though he was sure that the role would be too obvious in his case, with his personality and such. He waited while Karasuma picked the 'traitors' patiently. Simply keep an eye out, right? It wont be hard. He looked into people's souls to know them, figuratively.. For the moment he was planning it all out in his head, they all knew these woods pretty well by now, after all they went to school here and trained here a lot.
Curii Marshall
Curii had to take off her glasses first, setting them in their cases so the lens wont get smudged or scratched on accident. She was pretty curious who the traitors would be.. Another thing that made her nervous was, if she was chosen, would she be able to keep it together? Surely.. She was used to being quiet and not associating with too many people, and if she was a traitor then she knew ways to get out of being caught! These thoughts gave her a little more confidence, but she hoped not to embarrass herself through it all.