This is a useless action if they don't even know how to kill N. Unless he's trying to get N to kill himself in return for Kanzaki's life, I don't see how they're going to get out of this alive.
I think this could be beneficial. If N kills him then it'll be bad for the kanzaki as people would think worse of her. N wouldn't want that. In fact he'll hate it. Of course N is already shown to be unstable so who knows?