How do you get liquid deviance? Also what all would i need to trade for it?

What is pure snow and crystaline ice used for?

Sorry, im new and havent done any of these things yets.

You need to first get the Scheme: Deviance Extractor, then construct one. Use it on a deviant pet to get the liquid form. Also, you can't use it to make another pet deviant and the action is irreversible. What you would need to trade for it is a matter of opinion.

They are both needed to activate a Pristine Snowflake. There is an article about it in the official Tundra post on the front page.