Snapcaster Mage

Flash
When this creature enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Atraxa, Grand Unifier

Flying, vigilance, deathtouch, lifelink
When Atraxa enters, reveal the top ten cards of your library. For each card type, you may put a card of that type from among the revealed cards into your hand. Put the rest on the bottom of your library in a random order. (Artifact, battle, creature, enchantment, instant, land, planeswalker, and sorcery are card types.)

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.

Command Tower

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

Bayou

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Aura Shards

Whenever a creature you control enters, you may destroy target artifact or enchantment.

Damn

Destroy target creature. A creature destroyed this way can't be regenerated.
Overload {2}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Spellseeker

When this creature enters, you may search your library for an instant or sorcery card with mana value 2 or less, reveal it, put it into your hand, then shuffle.

Reliquary Tower

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

Heroic Intervention

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

Rhystic Study

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

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

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.

Tezzeret's Gambit

({U/P} can be paid with either {U} or 2 life.)
Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Scroll Rack

{1}, {T}: Exile any number of cards from your hand face down. Put that many cards from the top of your library into your hand. Then look at the exiled cards and put them on top of your library in any order.

Azorius Chancery

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

Sharae of Numbing Depths

When Sharae enters, tap target creature an opponent controls and put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Whenever you tap one or more untapped creatures your opponents control, draw a card. This ability triggers only once each turn.

Arcane Signet

Underground Sea

Atraxa, Praetors' Voice

Flying, vigilance, deathtouch, lifelink
At the beginning of your end step, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Boseiju, Who Endures

{T}: Add {G}.
Channel — {1}{G}, Discard this card: Destroy target artifact, enchantment, or nonbasic land an opponent controls. That player may search their library for a land card with a basic land type, put it onto the battlefield, then shuffle. This ability costs {1} less to activate for each legendary creature you control.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Watery Grave

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

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Dreamdew Entrancer

Reach
When this creature enters, tap up to one target creature and put three stun counters on it. If you control that creature, draw two cards.

Temple Garden

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

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Forest

Marsh Flats

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Eternal Witness

When this creature enters, you may return target card from your graveyard to your hand.

Mjölnir, Storm Hammer

When Mjölnir enters, attach it to target legendary creature you control.
Whenever equipped creature attacks, tap target creature defending player controls and put a stun counter on it. Then Mjölnir deals damage to each opponent equal to the number of tapped creatures that opponent controls.
Equip {4}

Phyresis Outbreak

Each opponent gets a poison counter. Then each creature your opponents control gets -1/-1 until end of turn for each poison counter its controller has.

Tundra

Lulu, Stern Guardian

Whenever an opponent attacks you, choose target creature attacking you. Put a stun counter on that creature.
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Overgrown Tomb

({T}: Add {B} or {G}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

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.)

Boggart Bog

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Boggart Trawler

When this creature enters, exile target player's graveyard.

Boggart Trawler // Boggart Bog

Misty Rainforest

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Scrubland

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap this artifact.

Simic Growth Chamber

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

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

Soulherder

Whenever a creature is exiled from the battlefield, put a +1/+1 counter on this creature.
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.

Nimble Larcenist

Flying
When this creature enters, target opponent reveals their hand. You choose an artifact, instant, or sorcery card from it and exile that card.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Y'shtola Rhul

At the beginning of your end step, exile target creature you control, then return it to the battlefield under its owner's control. Then if it's the first end step of the turn, there is an additional end step after this step.

Panharmonicon

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

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Coiling Oracle

When this creature enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

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.

Selesnya Sanctuary

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Swords to Plowshares

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

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Tataru Taru

When Tataru Taru enters, you draw a card and target opponent may draw a card.
Scions' Secretary — Whenever an opponent draws a card, if it isn't that player's turn, create a tapped Treasure token. This ability triggers only once each turn.

Plains

Orzhov Basilica

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Cloudshift

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

Omega, Heartless Evolution

Wave Cannon — When Omega enters, for each opponent, tap up to one target nonland permanent that opponent controls. Put X stun counters on each of those permanents and you gain X life, where X is the number of nonbasic lands you control. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Teferi, Time Raveler

Each opponent can cast spells only any time they could cast a sorcery.
+1: Until your next turn, you may cast sorcery spells as though they had flash.
−3: Return up to one target artifact, creature, or enchantment to its owner's hand. Draw a card.

Golgari Rot Farm

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Isochron Scepter

Imprint — When this artifact enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

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.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Ichor Rats

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When this creature enters, each player gets a poison counter.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Mystic Reflection

Choose target nonlegendary creature. The next time one or more creatures or planeswalkers enter this turn, they enter as copies of the chosen creature.
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.)

Fear of Sleep Paralysis

Flying
Eerie — Whenever this creature or another enchantment you control enters and whenever you fully unlock a Room, tap up to one target creature and put a stun counter on it.
Stun counters can't be removed from permanents your opponents control. (They won't untap if they have stun counters.)

Displacer Kitten

Avoidance — Whenever you cast a noncreature spell, exile up to one target nonland permanent you control, then return that card to the battlefield under its owner's control.

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.

Vraska, Betrayal's Sting

Compleated ({B/P} can be paid with {B} or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)
0: You draw a card and you lose 1 life. Proliferate.
−2: Target creature becomes a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color" and loses all other card types and abilities.
−9: If target player has fewer than nine poison counters, they get a number of poison counters equal to the difference.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Swamp

Breeding Pool

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

Windswept Heath

{T}, Pay 1 life, Sacrifice this land: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Kinnan, Bonder Prodigy

Whenever you tap a nonland permanent for mana, add one mana of any type that permanent produced.
{5}{G}{U}: Look at the top five cards of your library. You may put a non-Human creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Monstrosity of the Lake

When Monstrosity of the Lake enters, you may pay {5}. If you do, tap all creatures your opponents control, then put a stun counter on each of those creatures. (If a permanent with a stun counter would become untapped, remove one from it instead.)
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Metastatic Evangel

Whenever another nontoken creature you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Counterspell

Birds of Paradise

Island

Sol Ring

Bala Ged Sanctuary

Bala Ged Recovery

Return target card from your graveyard to your hand.

Bala Ged Recovery // Bala Ged Sanctuary

Tropical Island

Savannah

Ondu Skyruins

Ondu Inversion

Ondu Inversion // Ondu Skyruins

Hallowed Fountain

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

Flooded Strand

{T}, Pay 1 life, Sacrifice this land: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Emiel the Blessed

{3}: Exile another target creature you control, then return it to the battlefield under its owner's control.
Whenever another creature you control enters, you may pay {G/W}. If you do, put a +1/+1 counter on it. If it's a Unicorn, put two +1/+1 counters on it instead. ({G/W} can be paid with either {G} or {W}.)

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.

Unnatural Restoration

Return target permanent card from your graveyard to your hand. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)