Getting

Cone of Cold

Roll a d20.
1—9 | Tap all creatures your opponents control.
10—19 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps.
20 | Tap all creatures your opponents control. Those creatures don't untap during their controllers' next untap steps. Until your next turn, creatures your opponents control enter tapped.

Winter's Rest

Enchant creature
When Winter's Rest enters, tap enchanted creature.
As long as you control another snow permanent, enchanted creature doesn't untap during its controller's untap step.

Have

Hylda's Crown of Winter

{1}, {T}: Tap target creature. This ability costs {1} less to activate during your turn.
{3}, Sacrifice Hylda's Crown of Winter: Draw a card for each tapped creature your opponents control.

Freeze in Place

Tap target creature an opponent controls and put three stun counters on it. Scry 2. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Hylda of the Icy Crown

Whenever you tap an untapped creature an opponent controls, you may pay {1}. When you do, choose one —
• Create a 4/4 white and blue Elemental creature token.
• Put a +1/+1 counter on each creature you control.
• Scry 2, then draw a card.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Ascendant Spirit

{S}{S}: Ascendant Spirit becomes a Spirit Warrior with base power and toughness 2/3.
{S}{S}{S}: If Ascendant Spirit is a Warrior, put a flying counter on it and it becomes a Spirit Warrior Angel with base power and toughness 4/4.
{S}{S}{S}{S}: If Ascendant Spirit is an Angel, put two +1/+1 counters on it and it gains "Whenever this creature deals combat damage to a player, draw a card."

Iceberg Cancrix

Whenever another snow permanent you control enters, you may have target player mill two cards.

Icy Blast

Tap X target creatures.
Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

Sunstone

{2}, Sacrifice a snow land: Prevent all combat damage that would be dealt this turn.

Negate

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Frost Raptor

Flying
{S}{S}: Frost Raptor gains shroud until end of turn. ({S} can be paid with one mana from a snow source. A creature with shroud can't be the target of spells or abilities.)

Abominable Treefolk

Trample
Abominable Treefolk's power and toughness are each equal to the number of snow permanents you control.
When Abominable Treefolk enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Faceless Haven

{T}: Add {C}.
{S}{S}{S}: Faceless Haven 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.)

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters tapped.

Snow-Covered Forest

Explore

You may play an additional land this turn.
Draw a card.

Glacial Plating

Enchant creature
Cumulative upkeep {S} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it. {S} can be paid with one mana from a snow source.)
Enchanted creature gets +3/+3 for each age counter on Glacial Plating.

Snow Devil

Enchant creature
Enchanted creature has flying.
Enchanted creature has first strike as long as it's blocking and you control a snow land.

Moritte of the Frost

Changeling (This card is every creature type.)
You may have Moritte of the Frost enter as a copy of a permanent you control, except it's legendary and snow in addition to its other types and, if it's a creature, it enters with two additional +1/+1 counters on it and has changeling.

Snow-Covered Plains

Frostwalk Bastion

{T}: Add {C}.
{1}{S}: Until end of turn, Frostwalk Bastion becomes a 2/3 Construct artifact creature. It's still a land. ({S} can be paid with one mana from a snow source.)
Whenever Frostwalk Bastion deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

Glacial Floodplain

({T}: Add {W} or {U}.)
Glacial Floodplain enters tapped.

Saddled Rimestag

Saddled Rimestag gets +2/+2 as long as you had another creature enter the battlefield under your control this turn.

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.)

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control Time of Ice.
III — Return all tapped creatures to their owners' hands.

Ohran Viper

Whenever Ohran Viper deals combat damage to a creature, destroy that creature at end of combat.
Whenever Ohran Viper deals combat damage to a player, you may draw a card.

Entish Restoration

Sacrifice a land. Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle. If you control a creature with power 4 or greater, instead search your library for up to three basic land cards, put them onto the battlefield tapped, then shuffle.

Search for Glory

Search your library for a snow permanent card, a legendary card, or a Saga card, reveal it, put it into your hand, then shuffle. You gain 1 life for each {S} spent to cast this spell. ({S} is mana from a snow source.)

Spirit of the Aldergard

When Spirit of the Aldergard enters, search your library for a snow land card, reveal it, put it into your hand, then shuffle.
Spirit of the Aldergard gets +1/+0 for each other snow permanent you control.

Succumb to the Cold

Tap one or two target creatures an opponent controls. Put a stun counter on each of them. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Icebind Pillar

{S}, {T}: Tap target artifact or creature. ({S} can be paid with one mana from a snow source.)

Arctic Flats

Arctic Flats enters tapped.
{T}: Add {G} or {W}.

Counterspell

Icebreaker Kraken

This spell costs {1} less to cast for each snow land you control.
When Icebreaker Kraken enters, artifacts and creatures target opponent controls don't untap during that player's next untap step.
Return three snow lands you control to their owner's hand: Return Icebreaker Kraken to its owner's hand.

Boreal Druid

Centaur Omenreader

As long as Centaur Omenreader is tapped, creature spells you cast cost {2} less to cast.

Graven Lore

Scry X, where X is the amount of {S} spent to cast this spell, then draw three cards. ({S} is mana from a snow source.)

Avalanche Caller

{2}: Target snow land you control becomes a 4/4 Elemental creature with hexproof and haste until end of turn. It's still a land. (A creature with hexproof can't be the target of spells or abilities your opponents control.)

Overcome

Creatures you control get +2/+2 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Arctic Treeline

({T}: Add {G} or {W}.)
Arctic Treeline enters tapped.

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.

Adarkar Windform

Flying
{1}{S}: Target creature loses flying until end of turn. ({S} can be paid with one mana from a snow source.)

Rimewind Cryomancer

{1}, {T}: Counter target activated ability. Activate only if you control four or more snow permanents. (Mana abilities can't be targeted.)

Boreal Shelf

Boreal Shelf enters tapped.
{T}: Add {W} or {U}.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Boreal Centaur

{S}: Boreal Centaur gets +1/+1 until end of turn. Activate only once each turn. ({S} can be paid with one mana from a snow source.)

Wall of Shards

Defender, flying
Cumulative upkeep—An opponent gains 1 life. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Adarkar Valkyrie

Flying, vigilance
{T}: When target creature other than Adarkar Valkyrie dies this turn, return that card to the battlefield under your control.

Rime Tender

{T}: Untap another target snow permanent.

On Thin Ice

Enchant snow land you control
When On Thin Ice enters, exile target creature an opponent controls until On Thin Ice leaves the battlefield.

Ride the Avalanche

The next spell you cast this turn can be cast as though it had flash. When you next cast a spell this turn, put X +1/+1 counters on up to one target creature, where X is the mana value of that spell.

Icehide Golem

({S} can be paid with one mana from a snow source.)

Sol Ring

Frostweb Spider

Reach (This creature can block creatures with flying.)
Whenever Frostweb Spider blocks a creature with flying, put a +1/+1 counter on Frostweb Spider at end of combat.

Behemoth Sledge

Equipped creature gets +2/+2 and has trample and lifelink.
Equip {3}

Boreal Outrider

Whenever you cast a creature spell, if {S} of any of that spell's colors was spent to cast it, that creature enters with an additional +1/+1 counter on it. ({S} is mana from a snow source.)

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Mouth of Ronom

{T}: Add {C}.
{4}{S}, {T}, Sacrifice Mouth of Ronom: It deals 4 damage to target creature. ({S} can be paid with one mana from a snow source.)

Diamond Faerie

Flying
{1}{S}: Snow creatures you control get +1/+1 until end of turn. ({S} can be paid with one mana from a snow source.)

Blizzard Strix

Flash
Flying
When Blizzard Strix enters, if you control another snow permanent, exile target permanent other than Blizzard Strix. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Hurkyl's Recall

Return all artifacts target player owns to their hand.

Ice-Fang Coatl

Flash
Flying
When Ice-Fang Coatl enters, draw a card.
Ice-Fang Coatl has deathtouch as long as you control at least three other snow permanents.

Glittering Frost

Enchant land
Enchanted land is snow.
Whenever enchanted land is tapped for mana, its controller adds an additional one mana of any color.

Glacial Revelation

Reveal the top six cards of your library. You may put any number of snow permanent cards from among them into your hand. Put the rest into your graveyard.

Conifer Wurm

Trample
{3}{G}: Conifer Wurm gets +X/+X until end of turn, where X is the number of snow permanents you control.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Arcum's Astrolabe

({S} can be paid with one mana from a snow source.)
When Arcum's Astrolabe enters, draw a card.
{1}, {T}: Add one mana of any color.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Azusa, Lost but Seeking

You may play two additional lands on each of your turns.

Rimefeather Owl

Flying
Rimefeather Owl's power and toughness are each equal to the number of snow permanents on the battlefield.
{1}{S}: Put an ice counter on target permanent.
Permanents with ice counters on them are snow.

Vega, the Watcher

Flying
Whenever you cast a spell from anywhere other than your hand, draw a card.

Pilfering Hawk

Flying
{S}, {T}: Draw a card, then discard a card. ({S} can be paid with one mana from a snow source.)

Gelid Shackles

Enchant creature
Enchanted creature can't block, and its activated abilities can't be activated.
{S}: Enchanted creature gains defender until end of turn. ({S} can be paid with one mana from a snow source.)

Squall Drifter

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Snow-Covered Island

Into the North

Search your library for a snow land card, put it onto the battlefield tapped, then shuffle.

Cover of Winter

Cumulative upkeep {S} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it. {S} can be paid with one mana from a snow source.)
If a creature would deal combat damage to you and/or one or more creatures you control, prevent X of that damage, where X is the number of age counters on Cover of Winter.
{S}: Put an age counter on Cover of Winter.

Theft of Dreams

Draw a card for each tapped creature target opponent controls.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Sculptor of Winter

Blessing of Frost

Distribute X +1/+1 counters among any number of creatures you control, where X is the amount of {S} spent to cast this spell. Then draw a card for each creature you control with power 4 or greater.

Blizzard Brawl

Choose target creature you control and target creature you don't control. If you control three or more snow permanents, the creature you control gets +1/+0 and gains indestructible until end of turn. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

Shimmerdrift Vale

Shimmerdrift Vale enters tapped.
As Shimmerdrift Vale enters, choose a color.
{T}: Add one mana of the chosen color.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Isu the Abominable

You may look at the top card of your library any time.
You may play snow lands and cast snow spells from the top of your library.
Whenever another snow permanent you control enters, you may pay {G}, {W}, or {U}. If you do, put a +1/+1 counter on Isu the Abominable.