99.9% sure that a tvxq member will be a mentor. Idk about BoA since she was already a mentor on Broduce 101, idk if she liked being a mentor on there or not, but if she did then there’s a chance of her being a mentor again.
BoA or TVXQ would be great for MCs. As mentors, KARA Jiyoung would be good. Someone from 2PM or Shinee too, since they are all fluent in japanese, though I don't see Shinee members being involved right now.