Definitely supporting Cube for B rank. CB is just facemeltingly powerful, since not even ubers ferro can stop it. I've also had decent success with sub claws cube on a rain semi stall team. It is doomed to be revenge killed by basically all its dragon brethren, and despite being naturally bulky, it isn't going to be standing up to the really powerful attacks without investment. This considered, Kyurem Black is definitely B rank No love for Sawsbuck? Anyone?