Draugr Necromancer

If a nontoken creature an opponent controls would die, exile that card with an ice counter on it instead.
You may cast spells from among cards in exile your opponents own with ice counters on them, and you may spend mana from snow sources as though it were mana of any color to cast those spells.

Marit Lage's Slumber

Whenever Marit Lage's Slumber or another snow permanent you control enters, scry 1.
At the beginning of your upkeep, if you control ten or more snow permanents, sacrifice Marit Lage's Slumber. If you do, create Marit Lage, a legendary 20/20 black Avatar creature token with flying and indestructible.

Blood on the Snow

Choose one —
• Destroy all creatures.
• Destroy all planeswalkers.
Then return a creature or planeswalker card with mana value X or less from your graveyard to the battlefield, where X is the amount of {S} spent to cast this spell. ({S} is mana from a snow source.)

Grim Draugr

{1}{S}: This creature gets +1/+0 and gains menace until end of turn. (It can't be blocked except by two or more creatures. {S} can be paid with one mana from a snow source.)

Frost Augur

{S}, {T}: Look at the top card of your library. If it's a snow card, you may reveal it and put it into your hand. ({S} can be paid with one mana from a snow source.)

Priest of the Haunted Edge

{T}, Sacrifice this creature: Target creature gets -X/-X until end of turn, where X is the number of snow lands you control. Activate only as a sorcery.

Narfi, Betrayer King

Other snow and Zombie creatures you control get +1/+1.
{S}{S}{S}: Return this card from your graveyard to the battlefield tapped. ({S} can be paid with one mana from a snow source.)

Diregraf Captain

Deathtouch
Other Zombie creatures you control get +1/+1.
Whenever another Zombie you control dies, target opponent loses 1 life.

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: This land becomes a 4/3 creature with vigilance and all creature types until end of turn. It's still a land. ({S} can be paid with one mana from a snow source.)

Dead of Winter

All nonsnow creatures get -X/-X until end of turn, where X is the number of snow permanents you control.