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.)

Mountain

Exotic Orchard

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

Sol Ring

Arcanis the Omnipotent

{T}: Draw three cards.
{2}{U}{U}: Return Arcanis to its owner's hand.

Scuttling Sentinel

Flash
Vigilance
When this creature enters, put a +1/+1 counter on another target creature you control. Until end of turn, that creature becomes a blue Crab in addition to its other types and gains hexproof. (It can't be the target of spells or abilities your opponents control.)

Leaping Ambush

Target creature gets +1/+3 and gains reach until end of turn. Untap it.

Void Grafter

Devoid (This card has no color.)
Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, another target creature you control gains hexproof until end of turn.

Bountiful Landscape

{T}: Add {C}.
{T}, Sacrifice this land: Search your library for a basic Forest, Island, or Mountain card, put it onto the battlefield tapped, then shuffle.
Cycling {G}{U}{R} ({G}{U}{R}, Discard this card: Draw a card.)

Surrak Dragonclaw

Flash
This spell can't be countered.
Creature spells you control can't be countered.
Other creatures you control have trample.

Green Slime

Flash
When this creature enters, counter target activated or triggered ability from an artifact or enchantment source. If a permanent's ability is countered this way, destroy that permanent.
Foretell {G} (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.)

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Zulaport Duelist

Flash
When this creature enters, up to one target creature gets -2/-0 until end of turn. Its controller mills two cards. (They put the top two cards of their library into their graveyard.)

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.

Myriad Landscape

This land enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice this land: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Command Tower

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

The Blue Spirit

You may cast the first creature spell you cast each turn as though it had flash.
Whenever a nontoken creature you control enters during combat, draw a card.

Temple of Abandon

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {R} or {G}.

Mystic Snake

Flash
When this creature enters, counter target spell.

Arcane Signet

Temple of Epiphany

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {R}.

Haze Frog

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, prevent all combat damage that other creatures would deal this turn.

Wilderness Reclamation

At the beginning of your end step, untap all lands you control.

Omnath, Locus of the Roil

When Omnath enters, it deals damage to any target equal to the number of Elementals you control.
Landfall — Whenever a land you control enters, put a +1/+1 counter on target Elemental you control. If you control eight or more lands, draw a card.

Double Trouble

Double the power of each creature you control until end of turn.

Rubblehulk

Rubblehulk's power and toughness are each equal to the number of lands you control.
Bloodrush — {1}{R}{G}, Discard this card: Target attacking creature gets +X/+X until end of turn, where X is the number of lands you control.

Frontier Bivouac

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

Bounding Krasis

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, you may tap or untap target creature.

Mistcutter Hydra

This spell can't be countered.
Haste, protection from blue
This creature enters with X +1/+1 counters on it.

Rootbound Crag

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

Cleaver Riot

Creatures you control gain double strike until end of turn. (They deal both first-strike and regular combat damage.)

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Prime Speaker Zegana

Prime Speaker Zegana enters with X +1/+1 counters on it, where X is the greatest power among other creatures you control.
When Prime Speaker Zegana enters, draw cards equal to its power.

Humbling Elder

Flash
When this creature enters, target creature an opponent controls gets -2/-0 until end of turn.

Hinterland Harbor

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

Gainsay

Victory Chimes

Untap this artifact during each other player's untap step.
{T}: A player of your choice adds {C}.

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Guttural Response

Druid of Purification

When this creature enters, starting with you, each player may choose an artifact or enchantment you don't control. Destroy each permanent chosen this way.

Myconid Spore Tender

Infesting Spores — When this creature enters, destroy up to one target artifact or enchantment.

Terramorphic Expanse

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

Rattleclaw Mystic

{T}: Add {G}, {U}, or {R}.
Morph {2} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)
When this creature is turned face up, add {G}{U}{R}.

Wizards of Thay

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.)
Instant and sorcery spells you cast cost {1} less to cast.
You may cast sorcery spells as though they had flash.

Zimone, Quandrix Prodigy

{1}, {T}: You may put a land card from your hand onto the battlefield tapped.
{4}, {T}: Draw a card. If you control eight or more lands, draw two cards instead.

Xyris, the Writhing Storm

Flying
Whenever an opponent draws a card except the first one they draw in each of their draw steps, create a 1/1 green Snake creature token.
Whenever Xyris deals combat damage to a player, you and that player each draw that many cards.

Gretchen Titchwillow

{2}{G}{U}: Draw a card. You may put a land card from your hand onto the battlefield.

Reclamation Sage

When this creature enters, you may destroy target artifact or enchantment.

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.

Gulf Squid

When this creature enters, tap all lands target player controls.

Path of Ancestry

This land 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.)

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Brinebarrow Intruder

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Forest

Island

Mold Adder

Whenever an opponent casts a blue or black spell, you may put a +1/+1 counter on this creature.

Aquitect's Defenses

Flash
Enchant creature you control
When this Aura enters, enchanted creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
Enchanted creature gets +1/+2.

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.

Eshki Dragonclaw

Vigilance, trample, ward {1}
At the beginning of combat on your turn, if you've cast both a creature spell and a noncreature spell this turn, draw a card and put two +1/+1 counters on Eshki Dragonclaw.

Counterspell

Borborygmos and Fblthp

Whenever Borborygmos and Fblthp enters or attacks, draw a card, then you may discard any number of land cards. When you discard one or more cards this way, Borborygmos and Fblthp deals twice that much damage to target creature.
{1}{U}: Put Borborygmos and Fblthp into its owner's library third from the top.

Academy Loremaster

At the beginning of each player's draw step, that player may draw an additional card. If they do, spells they cast this turn cost {2} more to cast.

Frilled Mystic

Flash
When this creature enters, you may counter target spell.

Shambleshark

Flash (You may cast this spell any time you could cast an instant.)
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)

Archivist

Bulk Up

Double target creature's power until end of turn.
Flashback {4}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Dualcaster Mage

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

Witchstalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Whenever an opponent casts a blue or black spell during your turn, put a +1/+1 counter on this creature.

Final-Word Phantom

Flash
Flying
During each opponent's end step, you may cast spells as though they had flash.

Bender's Waterskin

Untap this artifact during each other player's untap step.
{T}: Add one mana of any color.

Magic Damper

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it.

Mosswort Bridge

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
This land enters tapped.
{T}: Add {G}.
{G}, {T}: You may play the exiled card without paying its mana cost if creatures you control have total power 10 or greater.

High Stride

Tifa's Limit Break

Tiered (Choose one additional cost.)
• Somersault — {0} — Target creature gets +2/+2 until end of turn.
• Meteor Strikes — {2} — Double target creature's power and toughness until end of turn.
• Final Heaven — {6}{G} — Triple target creature's power and toughness until end of turn.

Sulfur Falls

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

Bonny Pall, Clearcutter

Reach
When Bonny Pall enters, create Beau, a legendary blue Ox creature token with "Beau's power and toughness are each equal to the number of lands you control."
Whenever you attack, draw a card, then you may put a land card from your hand or graveyard onto the battlefield.

Unleash Fury

Double the power of target creature until end of turn.

Plumecreed Escort

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

Dragonclaw Strike

Double the power and toughness of target creature you control until end of turn. Then it fights up to one target creature an opponent controls. (Each deals damage equal to its power to the other.)

Octopus Form

Illvoi Light Jammer

Flash
When this Equipment enters, attach it to target creature you control. That creature gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)
Equipped creature gets +1/+2.
Equip {3}

Marcus, Mutant Mayor

Vigilance, trample
Whenever a creature you control deals combat damage to a player, draw a card if that creature has a +1/+1 counter on it. If it doesn't, put a +1/+1 counter on it.

Cogwork Wrestler

Temur Charm

Choose one —
• Target creature you control gets +1/+1 until end of turn. It fights target creature you don't control.
• Counter target spell unless its controller pays {3}.
• Creatures with power 3 or less can't block this turn.

Wildborn Preserver

Flash (You may cast this spell any time you could cast an instant.)
Reach (This creature can block creatures with flying.)
Whenever another non-Human creature you control enters, you may pay {X}. When you do, put X +1/+1 counters on this creature.

Exponential Growth

Until end of turn, double target creature's power X times.

Surrakar Spellblade

Whenever you cast an instant or sorcery spell, you may put a charge counter on this creature.
Whenever this creature deals combat damage to a player, you may draw X cards, where X is the number of charge counters on it.

Chomping Changeling

Changeling (This card is every creature type.)
When this creature enters, destroy up to one target artifact or enchantment.

Negate

Sudden Spinnerets

Target creature gets +1/+3 until end of turn. Put a reach counter on it. Untap it.

Ricochet Trap

If an opponent cast a blue spell this turn, you may pay {R} rather than pay this spell's mana cost.
Change the target of target spell with a single target.