Unsummon

Return target creature to its owner's hand.

Wall of Lost Thoughts

Defender
When Wall of Lost Thoughts enters, target player mills four cards.

Teferi's Tutelage

When Teferi's Tutelage enters, draw a card, then discard a card.
Whenever you draw a card, target opponent mills two cards. (They put the top two cards of their library into their graveyard.)

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Devourer of Memory

Whenever one or more cards are put into your graveyard from your library, Devourer of Memory gets +1/+1 until end of turn and can't be blocked this turn.
{1}{U}{B}: Mill a card.

Cling to Dust

Exile target card from a graveyard. If it was a creature card, you gain 3 life. Otherwise, you draw a card.
Escape—{3}{B}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Into the Story

This spell costs {3} less to cast if an opponent has seven or more cards in their graveyard.
Draw four cards.

Glacial Grasp

Tap target creature. Its controller mills two cards. That creature doesn't untap during its controller's next untap step. (They put the top two cards of their library into their graveyard.)
Draw a card.

Snow-Covered Swamp

Aether Spellbomb

{U}, Sacrifice Aether Spellbomb: Return target creature to its owner's hand.
{1}, Sacrifice Aether Spellbomb: Draw a card.

Snow-Covered Island

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Icebind Pillar

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

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Unsubstantiate

Return target spell or creature to its owner's hand.

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Iceberg Cancrix

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

Weight of Memory

Draw three cards. Target player mills three cards.

Sweet Oblivion

Target player mills four cards.
Escape—{3}{U}, Exile four other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Memorial to Genius

Memorial to Genius enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Memorial to Genius: Draw two cards.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.