Yay! I made it!
For anyone curious about my card:
The way it works is that you can’t just drop it on a column and deal immediate damage to whoever is on it. If the Snowstorm is dropped ON them, units leaving will take damage. However, when moving with cards like Silhouette Tracer, Mist Walking or Hearth-Sister, the unit will not take damage.
Obviously, this is designed to help Infiltrate. However, this also hurts you and your minions when crossing over, so be wary of friendly fire. This is ideally used when you’re in the middle column of the board, with a couple of Infiltrate minions set up; at 9 mana you can set up the Rhyno + Snowstorm to really lock them in.
The way these Snowstorm tiles are marked will be with a white tile effect (like Shadow Creep) that disappears at the start of your turn, so both sides know clearly where the Snowstorm is.
Thanks for reading, and thanks for the support!
–RyanH