What Pokemon evolve at the ice crystal in Twist Mountain Black and White?

There is no Pokemon evolution that requires the Ice Crystal in Twist Mountain in Pokemon Black and White.

The Ice Crystal is used for a different purpose: It's a key item for unlocking a secret area in Twist Mountain called the "Ice Path."

You can find this item at the end of the Ice Path. It's guarded by a Level 47 Cryogonal, a strong Pokemon.

If you're thinking of a different item or a different location, please let me know. I can help you figure out which Pokemon evolve where!