Have you considered Skred or Distortion Strike ? Skred fits your theme and typically kills what it hits. Distortion Strike could win you the game in two swings (or one with Marit Lage). Genesis Wave seems like it would also add to your deck by filling the field with snow permanents and you can hit most of the permanents in your deck with x=3/4. Hope this helps.

Thank you for this BSP! I was familiar with Skred and will take a closer look at the others!

Looks fun so far! I would HIGHLY recommend moving 3 or 4 Glacial Revelation to the mainboard - in a shell like this it's generally 3 mana to draw 4 or 5 cards.

Thank you Silverdrake! What would you take out from the deck to main board Glacial Revelation ?

That's a tough question. After a good look-over, I think I'd cut the Boreal Druid s. My thought process on that is this: generally, one-cmc mana dorks are most powerful and most useful when you're playing them on turn 1 to slam a high-power 3 drop on turn 2. The only thing you're running that I would consider being worth the dedicated dorks to be able to slam on turn 2 is Blood Moon - and in order to do that, you have to have exactly forest, boreal druid, blood moon, and either mountain or prismatic vista in your opening hand & first draw - since you're only running one mountain, that's highly unlikely.
I'm not saying Boreal Druid is a bad card, I'm just saying that in the type of shell you've built here I think more often than not when you draw it, you're going to wish you had drawn something else. That does bring your creature count a bit low though, and seeing how it's already on the lower end that's something we want to avoid. All things considered, here's what I'd do:
Cut: 1x Marit Lage's Slumber , 3x Growth Spiral , 1x Carnage Tyrant , 4x Boreal Druid
Add: 1x Into the North , 2x Assassin's Trophy , 2x Diamond Faerie , 4x Glacial Revelation

Of course, that's just my opinion. Whatever yuo decide to do, good luck and have fun with it!

Great thinking Silverdrake. I wonder if the Assassin's Trophy will undermine what I am trying to do with Blood Moon but I will keep it in for now.

That's definitely a possibility, I just like its flexibility. Pioneer is a planeswalker-heavy format so you want something that can hit them - if you don't like how the Assassin's Trophys play, you could swap them out for Hero's Downfall , Ruinous Path , Vraska's Contempt , Abrupt Decay , Dreadbore , Bedevil , or Murderous Rider . I would try to steer away from the options that cost double black though, since that'll complicate your mana base.

Or you could replace them with something else you like, like a creature or enchantment or something. It's your deck, after all!

should've called it yellow snow (b/c multicolored)

jonmaior I suppose that would be another good name; but yellow snow is best to be avoided... :)