Cryogonal, though a bit of a one-shot cannon when it comes to battling other pokemon, is nevertheless a great choice if you want to bring down the champion in Pokemon Black and White 2 in a big hurry. So where do you find one of these weird-looking pokemon? They appeared on Twist Mountain before, and as most players will discover, you can't get into Twist Mountain in Pokemon Black and White 2.
This last part is actually just a misconception from players who haven't BEATEN said game at least once. After you've trounced the Elite Four and the champion a single time, Twist Mountain will be open for business on both ends. Fly to Mistralton City and you can walk right in and find a Cryogonal. Once again, this is the only place to find them in the game.
... which means that you can't rely on a Cryogonal to help you beat the champion on your first ride through. Dang. Well, there are always trades, right?