Fear of Impostors

Flash
When this creature enters, counter target spell. Its controller manifests dread. (That player looks at the top two cards of their library, then puts one onto the battlefield face down as a 2/2 creature and the other into their graveyard. If it's a creature card, it can be turned face up any time for its mana cost.)

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.)

Portal Manipulator

Flash
When this creature enters during the declare attackers step, choose target player and any number of target attacking creatures their opponents control. Those creatures are now attacking that player.

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Render Silent

Counter target spell. Its controller can't cast spells this turn.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Mountain

Inexorable Tide

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Clifftop Retreat

This land enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Hydroelectric Laboratory

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

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

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.)

Cathar Commando

Flash
{1}, Sacrifice this creature: Destroy target artifact or enchantment.

Exotic Orchard

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

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. This artifact deals 1 damage to you.

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Frostcliff Siege

As this enchantment enters, choose Jeskai or Temur.
• Jeskai — Whenever one or more creatures you control deal combat damage to a player, draw a card.
• Temur — Creatures you control get +1/+0 and have trample and haste.

Radiant Performer

Flash
When this creature enters, if you cast it from your hand, choose target spell or ability that targets only a single permanent or player. Copy that spell or ability for each other permanent or player the spell or ability could target. Each copy targets a different one of those permanents and players.

Plains

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Transcendent Dragon

Flash
Flying
When this creature enters, if you cast it, counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard, then you may cast it without paying its mana cost.

Vexilus Praetor

Flash
Vigilance
Aegis of the Emperor — Commanders you control have protection from everything.

Draining Whelk

Flash
Flying
When this creature enters, counter target spell. Put X +1/+1 counters on this creature, where X is that spell's mana value.

Guardian of Faith

Flash
Vigilance
When this creature enters, any number of other target creatures you control phase out. (Treat them and anything attached to them as though they don't exist until their controller's next turn.)

Minas Tirith

Minas Tirith enters tapped unless you control a legendary creature.
{T}: Add {W}.
{1}{W}, {T}: Draw a card. Activate only if you attacked with two or more creatures this turn.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

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.

Stroke of Midnight

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

Plumecreed Escort

Flash
Flying
When this creature enters, target creature you control gains hexproof until end of turn.

Aqueous Form

Enchant creature
Enchanted creature can't be blocked.
Whenever enchanted creature attacks, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Errant and Giada

Flash
Flying
You may look at the top card of your library any time.
You may cast spells with flash or flying from the top of your library.

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.)

Dualcaster Mage

Flash
When this creature enters, copy target instant or sorcery spell. You may choose new targets for the copy.

Gatta and Luzzu

Flash
When Gatta and Luzzu enters, choose target creature you control. If damage would be dealt to that creature this turn, prevent that damage and put that many +1/+1 counters on it.

Sonic the Hedgehog

Haste
Gotta Go Fast — Whenever Sonic the Hedgehog attacks, put a +1/+1 counter on each creature you control with flash or haste.
Whenever a creature you control with flash or haste is dealt damage, create a tapped Treasure token.

Spell Queller

Flash
Flying
When this creature enters, exile target spell with mana value 4 or less.
When this creature leaves the battlefield, the exiled card's owner may cast that card without paying its mana cost.

Chart a Course

Draw two cards. Then discard a card unless you attacked this turn.

Demolition Field

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

Cloudshift

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

Malleable Impostor

Flash
Flying
You may have this creature enter as a copy of a creature an opponent controls, except it's a Faerie Shapeshifter in addition to its other types and it has flying.

Blitzball Stadium

When this artifact enters, support X. (Put a +1/+1 counter on each of up to X target creatures.)
Go for the Goal! — {3}, {T}: Until end of turn, target creature gains "Whenever this creature deals combat damage to a player, draw a card for each kind of counter on it" and it can't be blocked this turn.

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.)

Dovin's Veto

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

Reliquary Tower

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

Avacyn, the Purifier

Flying
When this creature transforms into Avacyn, the Purifier, it deals 3 damage to each other creature and each opponent.

Archangel Avacyn

Flash
Flying, vigilance
When Archangel Avacyn enters, creatures you control gain indestructible until end of turn.
When a non-Angel creature you control dies, transform Archangel Avacyn at the beginning of the next upkeep.

Archangel Avacyn // Avacyn, the Purifier

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Disruption Protocol

As an additional cost to cast this spell, tap an untapped artifact you control or pay {1}.
Counter target spell.

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

Whitemane Lion

Flash
When this creature enters, return a creature you control to its owner's hand.

Full Throttle

After this main phase, there are two additional combat phases.
At the beginning of each combat this turn, untap all creatures that attacked this turn.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Negate

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Muraganda Raceway

Start your engines! (If you have no speed, it starts at 1. It increases once on each of your turns when an opponent loses life. Max speed is 4.)
{T}: Add {C}.
Max speed — {T}: Add {C}{C}.

Nimble Obstructionist

Flash
Flying
Cycling {2}{U} ({2}{U}, Discard this card: Draw a card.)
When you cycle this card, counter target activated or triggered ability you don't control.

Angel of the Dire Hour

Flash
Flying
When this creature enters, if you cast it from your hand, exile all attacking creatures.

Sublime Epiphany

Choose one or more —
• Counter target spell.
• Counter target activated or triggered ability.
• Return target nonland permanent to its owner's hand.
• Create a token that's a copy of target creature you control.
• Target player draws a card.

Sicarian Infiltrator

Flash
Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Benediction of the Omnissiah — When this creature enters, draw a card.

Command Tower

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

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Thought Sponge

Flash
This creature enters with a number of +1/+1 counters on it equal to the greatest number of cards an opponent has drawn this turn.
When this creature dies, draw cards equal to its power.

Tishana's Tidebinder

Flash
When this creature enters, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as this creature remains on the battlefield. (Mana abilities can't be targeted.)

Stunt Double

Flash
You may have this creature enter as a copy of any creature on the battlefield.

Mizzium Meddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, you may change a target of target spell or ability to this creature.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Swords to Plowshares

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

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Dragonfire Blade

Equipped creature gets +2/+2 and has hexproof from monocolored.
Equip {4}. This ability costs {1} less to activate for each color of the creature it targets.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Wave Goodbye

Return each creature without a +1/+1 counter on it to its owner's hand.

The Wandering Rescuer

Flash
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Double strike
Other tapped creatures you control have hexproof.

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser enters, return target spell or permanent to its owner's hand.

Sol Ring

Arcane Signet

Smirking Spelljacker

Flash
Flying
When this creature enters, exile target spell an opponent controls.
Whenever this creature attacks, if a card is exiled with it, you may cast the exiled card without paying its mana cost.

Island

Counterspell

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Windcrag Siege

As this enchantment enters, choose Mardu or Jeskai.
• Mardu — If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
• Jeskai — At the beginning of your upkeep, create a 1/1 red Goblin creature token. It gains lifelink and haste until end of turn.

Githzerai Monk

Flash
Flying
Psychic Defense — When this creature enters, tap all creatures you don't control.

Crafty Cutpurse

Flash
When this creature enters, each token that would be created under an opponent's control this turn is created under your control instead.