There is no reward out on any of these villains. However, if the characters were able to defeat Snowman without a direct confrontation, add .5 to the Training Point Multiplier of the characters involved.
If the players fail and Snowman does cover the world with his storm, you’ve got a new world. If the characters are defeated in the castle, any survivors will be set loose in the arctic—200 kilometers from nowhere. The Snowman has no need for prisoners. Any part of the world that is covered by the storm is cut off from everywhere else. The storm will only have 60 kmph winds outside of the arctic area, and the temperature will vary from -20 degrees to 2 degrees celsius . All roads will be closed. Planes will be grounded. Power lines will go down, as will most outdoor antennas. The world will be thrown into chaos as the storm grows wider and wider. I’m sure you can take it from there.