Mana Leak

Counter target spell unless its controller pays {3}.

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Altar of the Brood

Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

Abjure

As an additional cost to cast this spell, sacrifice a blue permanent.
Counter target spell.

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.

Halimar Depths

Halimar Depths enters the battlefield tapped.
When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters the battlefield tapped unless you control three or more other Islands.
When Mystic Sanctuary enters the battlefield untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Memory Erosion

Whenever an opponent casts a spell, that player mills two cards.

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sol Ring

Court of Cunning

When Court of Cunning enters the battlefield, you become the monarch.
At the beginning of your upkeep, any number of target players each mill two cards. If you're the monarch, each of those players mills ten cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Drowned Secrets

Whenever you cast a blue spell, target player mills two 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.)

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Snow-Covered Plains

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Arcane Adaptation

As Arcane Adaptation enters the battlefield, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Brain Freeze

Target player mills three cards.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Riddlekeeper

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

Ghostly Prison

Dovin's Veto

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

Ruin Crab

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

Fractured Sanity

Each opponent mills fourteen cards.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Fractured Sanity, each opponent mills four cards.

Thought Scour

Target player mills two cards.
Draw a card.

Hall of Storm Giants

If you control two or more other lands, Hall of Storm Giants enters the battlefield tapped.
{T}: Add {U}.
{5}{U}: Until end of turn, Hall of Storm Giants becomes a 7/7 blue Giant creature with ward {3}. It's still a land. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Terminus

Put all creatures on the bottom of their owners' libraries.
Miracle {W} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Fabled Passage

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Teferi's Tutelage

When Teferi's Tutelage enters the battlefield, 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.)

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Jwari Ruins

Jwari Ruins enters the battlefield tapped.
{T}: Add {U}.

Jwari Disruption

Counter target spell unless its controller pays {1}.

Jwari Disruption // Jwari Ruins

Calciform Pools

{T}: Add {C}.
{1}, {T}: Put a storage counter on Calciform Pools.
{1}, Remove X storage counters from Calciform Pools: Add X mana in any combination of {W} and/or {U}.

Thought Collapse

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Command Tower

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

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

Fleet Swallower

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

Azorius Signet

Hedron Crab

Landfall — Whenever a land enters the battlefield under your control, target player mills three cards.

Deserted Beach

Deserted Beach enters the battlefield tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Folk Hero

Commander creatures you own have "Whenever you cast a spell that shares a creature type with this creature, draw a card. This ability triggers only once each turn."

Terisian Mindbreaker

Whenever Terisian Mindbreaker attacks, defending player mills half their library, rounded up.
Unearth {1}{U}{U}{U} ({1}{U}{U}{U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters the battlefield tapped unless you control two or more basic lands.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Snow-Covered Island

Castle Vantress

Castle Vantress enters the battlefield tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Swords to Plowshares

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

Arcane Signet

Sphinx's Tutelage

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process.
{5}{U}: Draw a card, then discard a card.

Port Town

As Port Town enters the battlefield, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters the battlefield tapped.
{T}: Add {W} or {U}.

Vantress Gargoyle

Flying
Vantress Gargoyle can't attack unless defending player has seven or more cards in their graveyard.
Vantress Gargoyle can't block unless you have four or more cards in hand.
{T}: Each player mills a card.

Overwhelmed Apprentice

When Overwhelmed Apprentice enters the battlefield, each opponent mills two cards. Then you scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Mistgate Pathway

Hengegate Pathway

Hengegate Pathway // Mistgate Pathway

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. Talisman of Progress deals 1 damage to you.

Zellix, Sanity Flayer

Hive Mind — Whenever a player mills one or more creature cards, you create a 1/1 black Horror creature token.
{1}, {T}: Target player mills three cards.
Choose a Background (You can have a Background as a second commander.)

Rebuff the Wicked

Counter target spell that targets a permanent you control.

Maddening Cacophony

Kicker {3}{U}
Each opponent mills eight cards. If this spell was kicked, instead each opponent mills half their library, rounded up.

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.