Q: Fluffy white Snow powder is sprayed from his flamethrower
W: A big glass ball surrounds him with snow sprinkling down inside.. Similar to a snow globe. When shielded, snow trails behind him then melts to water
E: Snowballs are thrown! When not used for a while the size of the snowball increases to a cap.
R: As his Ult falls, snow showers down from the sky, the area where his ult lands becomes little snow piles with maybe a snowman in the middle
Rumble is decorated in a bunch of misplaced holiday lights, with maybe some holiday boots on his robot's feet, and a santa hat!
When he overheats, snow lightly showers on to him to cool off.
His Mace is replaced by a snow shovel and on his back instead of rockets, he has a bag full of snowballs all differently sized with maybe 3 larger snowballs to form a snowman when ult comes down.
Upvote if you like the idea! :3