Counterspell

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

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.

Spirited Companion

When Spirited Companion enters, draw a card.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Overlord of the Floodpits

Impending 4—{1}{U}{U} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Flying
Whenever Overlord of the Floodpits enters or attacks, draw two cards, then discard a card.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Teleportation Circle

At the beginning of your end step, exile up to one target artifact or creature you control, then return that card to the battlefield under its owner's control.

Mystic Gate

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

Niko, Light of Hope

When Niko, Light of Hope enters, create two Shard tokens. (They're enchantments with "{2}, Sacrifice this enchantment: Scry 1, then draw a card.")
{2}, {T}: Exile target nonlegendary creature you control. Shards you control become copies of it until the beginning of the next end step. Return it to the battlefield under its owner's control at the beginning of the next end step.

Rhystic Study

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

Preston, the Vanisher

Whenever another nontoken creature you control enters, if it wasn't cast, create a token that's a copy of that creature, except it's a 0/1 white Illusion.
{1}{W}, Sacrifice five Illusions: Exile target nonland permanent.

Sol Ring

Time Wipe

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

Nesting Dovehawk

Flying
At the beginning of combat on your turn, populate. (Create a token that's a copy of a creature token you control.)
Whenever a creature token you control enters, put a +1/+1 counter on Nesting Dovehawk.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Entity Tracker

Flash
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, draw a card.

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Fortune, Loyal Steed

When Fortune, Loyal Steed enters, scry 2.
Whenever Fortune attacks while saddled, at end of combat, exile it and up to one creature that saddled it this turn, then return those cards to the battlefield under their owner's control.
Saddle 1

Mulldrifter

Flying
When Mulldrifter enters, draw two cards.
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Glacial Fortress

Glacial Fortress enters 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.

Skycloud Expanse

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Niko Aris

When Niko Aris enters, create X Shard tokens. (They're enchantments with "{2}, Sacrifice this enchantment: Scry 1, then draw a card.")
+1: Up to one target creature you control can't be blocked this turn. Whenever that creature deals damage this turn, return it to its owner's hand.
−1: Niko Aris deals 2 damage to target tapped creature for each card you've drawn this turn.
−1: Create a Shard token.

Ghostly Dancers

Flying
When Ghostly Dancers enters, return an enchantment card from your graveyard to your hand or unlock a locked door of a Room you control.
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, create a 3/1 white Spirit creature token with flying.

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Dream Trawler

Flying, lifelink
Whenever you draw a card, Dream Trawler gets +1/+0 until end of turn.
Whenever Dream Trawler attacks, draw a card.
Discard a card: Dream Trawler gains hexproof until end of turn. Tap it.

Archon of Sun's Grace

Flying, lifelink
Pegasus creatures you control have lifelink.
Constellation — Whenever an enchantment you control enters, create a 2/2 white Pegasus creature token with flying.

Restoration Angel

Flash
Flying
When Restoration Angel enters, you may exile target non-Angel creature you control, then return that card to the battlefield under your control.

Sun Titan

Vigilance
Whenever Sun Titan enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Moonshaker Cavalry

Flying
When Moonshaker Cavalry enters, creatures you control gain flying and get +X/+X until end of turn, where X is the number of creatures you control.

Ethereal Valkyrie

Flying
Whenever Ethereal Valkyrie enters or attacks, draw a card, then exile a card from your hand face down. It becomes foretold. Its foretell cost is its mana cost reduced by {2}. (On a later turn, you may cast it for its foretell cost, even if this creature has left the battlefield.)

Swords to Plowshares

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

Propaganda

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

Azure Beastbinder

Vigilance
Azure Beastbinder can't be blocked by creatures with power 2 or greater.
Whenever Azure Beastbinder attacks, up to one target artifact, creature, or planeswalker an opponent controls loses all abilities until your next turn. If it's a creature, it also has base power and toughness 2/2 until your next turn.

Silverwing Squadron

Flying, vigilance
Silverwing Squadron's power and toughness are each equal to the number of creatures you control.
Whenever Silverwing Squadron attacks, create a number of 2/2 white Knight creature tokens with vigilance equal to the number of opponents you have.

Phelia, Exuberant Shepherd

Flash
Whenever Phelia, Exuberant Shepherd attacks, exile up to one other target nonland permanent. At the beginning of the next end step, return that card to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on Phelia.

Generous Gift

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

Aerial Extortionist

Flying
Whenever Aerial Extortionist enters or deals combat damage to a player, exile up to one target nonland permanent. For as long as that card remains exiled, its owner may cast it.
Whenever another player casts a spell from anywhere other than their hand, draw a card.

Enduring Curiosity

Flash
Whenever a creature you control deals combat damage to a player, draw a card.
When Enduring Curiosity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Overlord of the Mistmoors

Impending 4—{2}{W}{W} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever Overlord of the Mistmoors enters or attacks, create two 2/1 white Insect creature tokens with flying.

Skybind

Constellation — Whenever Skybind or another enchantment you control enters, exile target nonenchantment permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Hallowed Fountain

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

Strionic Resonator

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Gremlin Tamer

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, create a 1/1 red Gremlin creature token.

Peregrine Drake

Flying
When Peregrine Drake enters, untap up to five lands.

Abuelo, Ancestral Echo

Flying, ward {2}
{1}{W}{U}: Exile another target creature or artifact you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

Nulldrifter

When you cast this spell, draw two cards.
Flying
Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent.)
Evoke {2}{U} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters.)

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on Soulherder.
At the beginning of your end step, you may exile another target creature you control, then return that card to the battlefield under its owner's control.

Boon of the Spirit Realm

Constellation — Whenever Boon of the Spirit Realm or another enchantment you control enters, put a blessing counter on Boon of the Spirit Realm.
Creatures you control get +1/+1 for each blessing counter on Boon of the Spirit Realm.

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Temple of Enlightenment

Temple of Enlightenment enters tapped.
When Temple of Enlightenment enters, scry 1.
{T}: Add {W} or {U}.

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.

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Ghostway

Exile each creature you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Vantress Visions

Copy target activated or triggered ability you control. You may choose new targets for the copy.

Virtue of Knowledge

If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Virtue of Knowledge // Vantress Visions

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Cloudshift

Exile target creature you control, then return that card to the battlefield under your control.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Another Round

Exile any number of creatures you control, then return them to the battlefield under their owner's control. Then repeat this process X more times.

Negate

Plains

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

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.

Arcane Signet

The Eternal Wanderer

No more than one creature can attack The Eternal Wanderer each combat.
+1: Exile up to one target artifact or creature. Return that card to the battlefield under its owner's control at the beginning of that player's next end step.
0: Create a 2/2 white Samurai creature token with double strike.
−4: For each player, choose a creature that player controls. Each player sacrifices all creatures they control not chosen this way.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.

Adarkar Wastes

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

Yorion, Sky Nomad

Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
Flying
When Yorion enters, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step.

Broodbirth Viper

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Whenever Broodbirth Viper deals combat damage to a player, you may draw a card.

Astral Dragon

Flying
Project Image — When Astral Dragon enters, create two tokens that are copies of target noncreature permanent, except they're 3/3 Dragon creatures in addition to their other types, and they have flying.

Tranquil Cove

Tranquil Cove enters tapped.
When Tranquil Cove enters, you gain 1 life.
{T}: Add {W} or {U}.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Hero of Bladehold

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Whenever Hero of Bladehold attacks, create two 1/1 white Soldier creature tokens that are tapped and attacking.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Beguiler of Wills

{T}: Gain control of target creature with power less than or equal to the number of creatures you control.

Elesh Norn, Mother of Machines

Vigilance
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Permanents entering don't cause abilities of permanents your opponents control to trigger.

Sphere of Safety

Creatures can't attack you or planeswalkers you control unless their controller pays {X} for each of those creatures, where X is the number of enchantments you control.

Song of the Worldsoul

Whenever you cast a spell, populate. (Create a token that's a copy of a creature token you control.)

Thought Vessel

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

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Azorius Signet

Terramorphic Expanse

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

Reliquary Tower

Lae'zel's Acrobatics

Exile all nontoken creatures you control, then roll a d20.
1—9 | Return those cards to the battlefield under their owner's control at the beginning of the next end step.
10—20 | Return those cards to the battlefield under their owner's control, then exile them again. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

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.")

Curiosity Crafter

Flying
You have no maximum hand size.
Whenever a creature token you control deals combat damage to a player, draw a card.

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Evolving Wilds

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

Deserted Beach

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

Ghostly Prison

Ephemerate

Exile target creature you control, then return it to the battlefield under its owner's control.
Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Battle Angels of Tyr

Flying, myriad
Whenever Battle Angels of Tyr deals combat damage to a player, draw a card if that player has more cards in hand than each other player. Then you create a Treasure token if that player controls more lands than each other player. Then you gain 3 life if that player has more life than each other player.

Exotic Orchard

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