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.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Containment Priest

Flash
If a nontoken creature would enter the battlefield and it wasn't cast, exile it instead.

Final-Word Phantom

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

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters the battlefield, destroy up to one target creature and target player mills three cards.

Dimir Signet

Crafty Cutpurse

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

Venser, Shaper Savant

Flash
When Venser, Shaper Savant enters the battlefield, return target spell or permanent to its owner's hand.

Arcane Sanctum

Arcane Sanctum enters the battlefield tapped.
{T}: Add {W}, {U}, or {B}.

Naiad of Hidden Coves

As long as it's not your turn, spells you cast cost {1} less to cast.

Final Showdown

Spree (Choose one or more additional costs.)
+ {1} — All creatures lose all abilities until end of turn.
+ {1} — Choose a creature you control. It gains indestructible until end of turn.
+ {3}{W}{W} — Destroy all creatures.

Lobelia Sackville-Baggins

Flash
Menace
When Lobelia Sackville-Baggins enters the battlefield, exile target creature card from an opponent's graveyard that was put there from the battlefield this turn, then create X Treasure tokens, where X is the exiled card's power.

Slitherwisp

Flash
Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

Stinging Study

You draw X cards and you lose X life, where X is the mana value of a commander you own on the battlefield or in the command zone.

Portal Manipulator

Flash
When Portal Manipulator enters the battlefield 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.

Terramorphic Expanse

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

Temple of Silence

Temple of Silence enters the battlefield tapped.
When Temple of Silence enters the battlefield, scry 1.
{T}: Add {W} or {B}.

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.

Chromium, the Mutable

Flash
This spell can't be countered.
Flying
Discard a card: Until end of turn, Chromium, the Mutable becomes a Human with base power and toughness 1/1, loses all abilities, and gains hexproof. It can't be blocked this 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.

Obscura Interceptor

Flash
Lifelink
When Obscura Interceptor enters the battlefield, it connives. When it connives this way, return up to one target spell to its owner's hand. (To have a creature connive, draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Imprisoned in the Moon

Enchant creature, land, or planeswalker
Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Eaten by Piranhas

Flash
Enchant creature
Enchanted creature loses all abilities and is a black Skeleton creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Reprieve

Return target spell to its owner's hand.
Draw a card.

Lavinia, Foil to Conspiracy

Vigilance
Whenever you cast your second spell each turn, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{T}: Add {C}{C}. Activate only during an opponent's turn.

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.

Windshaper Planetar

Flash
Flying
When Windshaper Planetar enters the battlefield during the declare attackers step, for each attacking creature, you may reselect which player or permanent that creature is attacking. (It can't attack its controller or their permanents.)

Tishana's Tidebinder

Flash
When Tishana's Tidebinder enters the battlefield, 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 Tishana's Tidebinder remains on the battlefield. (Mana abilities can't be targeted.)

Isolated Chapel

Isolated Chapel enters the battlefield tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Darkwater Catacombs

Thryx, the Sudden Storm

Flash
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Blightwing Bandit

Flying, deathtouch
Whenever you cast your first spell during each opponent's turn, look at the top card of that player's library, then exile it face down. You may play that card for as long as it remains exiled, and mana of any type can be spent to cast it.

Norn's Annex

({W/P} can be paid with either {W} or 2 life.)
Creatures can't attack you or planeswalkers you control unless their controller pays {W/P} for each of those creatures.

Command Tower

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

Island

Malcolm, Alluring Scoundrel

Flash
Flying
Whenever Malcolm, Alluring Scoundrel deals combat damage to a player, put a chorus counter on it. Draw a card, then discard a card. If there are four or more chorus counters on Malcolm, you may cast the discarded card without paying its mana cost.

Obelisk of Esper

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Lochmere Serpent

Flash
{U}, Sacrifice an Island: Lochmere Serpent can't be blocked this turn.
{B}, Sacrifice a Swamp: You gain 1 life and draw a card.
{U}{B}: Exile five target cards from an opponent's graveyard. Return Lochmere Serpent from your graveyard to your hand. Activate only as a sorcery.

Obscura Charm

Choose one —
• Return target multicolored permanent card with mana value 3 or less from your graveyard to the battlefield tapped.
• Counter target instant or sorcery spell.
• Destroy target creature or planeswalker with mana value 3 or less.

Ertai Resurrected

Flash
When Ertai Resurrected enters the battlefield, choose up to one —
• Counter target spell, activated ability, or triggered ability. Its controller draws a card.
• Destroy another target creature or planeswalker. Its controller draws a card.

Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter the battlefield under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Sphinx's Revelation

Spectral Sailor

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

Prairie Stream

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

Solemn Simulacrum

When Solemn Simulacrum enters the battlefield, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Rewind

Counter target spell. Untap up to four lands.

Adarkar Wastes

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

Nymris, Oona's Trickster

Flash
Flying
Whenever you cast your first spell during each opponent's turn, look at the top two cards of your library. Put one of those cards into your hand and the other into your graveyard.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Mocking Doppelganger

Flash
You may have Mocking Doppelganger enter the battlefield as a copy of a creature an opponent controls, except it has "Other creatures with the same name as this creature are goaded." (They attack each combat if able and attack a player other than you if able.)

Solitude

Flash
Lifelink
When Solitude enters the battlefield, exile up to one other target creature. That creature's controller gains life equal to its power.
Evoke—Exile a white card from your hand.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Deadeye Navigator

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Deadeye Navigator is paired with another creature, each of those creatures has "{1}{U}: Exile this creature, then return it to the battlefield under your control."

Chromatic Lantern

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

Propaganda

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

Ephara, God of the Polis

Indestructible
As long as your devotion to white and blue is less than seven, Ephara isn't a creature.
At the beginning of each upkeep, if you had another creature enter the battlefield under your control last turn, draw a card.

Activated Sleeper

Flash
You may have Activated Sleeper enter the battlefield as a copy of any creature card in a graveyard that was put there from the battlefield this turn, except it's a Phyrexian in addition to its other types.

Negate

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. Underground River deals 1 damage to you.

Jem Lightfoote, Sky Explorer

Flying, vigilance
At the beginning of your end step, if you haven't cast a spell from your hand this turn, draw a card.

Dovin's Veto

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

Sram, Senior Edificer

Whenever you cast an Aura, Equipment, or Vehicle spell, draw a card.

Unwind

Counter target noncreature spell. Untap up to three lands.

Guardian of Faith

Flash
Vigilance
When Guardian of Faith enters the battlefield, 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.)

Stunt Double

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

Cathar Commando

Flash
{1}, Sacrifice Cathar Commando: Destroy target artifact or enchantment.

Cunning Nightbonder

Flash
Spells with flash you cast cost {1} less to cast and can't be countered.

Geyser Drake

Flying
As long as it's not your turn, spells you cast cost {1} less to cast.

Arcane Signet

Temple of Deceit

Temple of Deceit enters the battlefield tapped.
When Temple of Deceit enters the battlefield, scry 1.
{T}: Add {U} or {B}.

Despark

Exile target permanent with mana value 4 or greater.

Weeping Angel

Flash
First strike, vigilance
Whenever an opponent casts a creature spell, Weeping Angel isn't a creature until end of turn.
If Weeping Angel would deal combat damage to a creature, prevent that damage and that creature's owner shuffles it into their library.

Cast Out

Flash
When Cast Out enters the battlefield, exile target nonland permanent an opponent controls until Cast Out leaves the battlefield.
Cycling {W} ({W}, Discard this card: Draw a card.)

Victory Chimes

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

Archivist of Oghma

Flash
Whenever an opponent searches their library, you gain 1 life and draw a card.

Blue Sun's Zenith

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Mystical Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.
Flashback {5}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Reliquary Tower

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

Angel of the Dire Hour

Flash
Flying
When Angel of the Dire Hour enters the battlefield, if you cast it from your hand, exile all attacking creatures.

Isochron Scepter

Imprint — When Isochron Scepter enters the battlefield, 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.

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 the battlefield, create that many tokens that are copies of it.)
Benediction of the Omnissiah — When Sicarian Infiltrator enters the battlefield, draw a card.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters the battlefield, draw a card.

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Malleable Impostor

Flash
Flying
You may have Malleable Impostor enter the battlefield 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.

Commander's Sphere

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

Remand

Counter target spell. If that spell is countered this way, put it into its owner's hand instead of into that player's graveyard.
Draw a card.

Nimble Obstructionist

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

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Claim Jumper

Vigilance
When Claim Jumper enters the battlefield, if an opponent controls more lands than you, you may search your library for a Plains card and put it onto the battlefield tapped. Then if an opponent controls more lands than you, repeat this process once. If you search your library this way, shuffle.

Swamp

Glacial Fortress

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

Restoration Angel

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

Dramatic Reversal

Untap all nonland permanents you control.

Orzhov Signet

Alela, Cunning Conqueror

Flying
Whenever you cast your first spell during each opponent's turn, create a 1/1 black Faerie Rogue creature token with flying.
Whenever one or more Faeries you control deal combat damage to a player, goad target creature that player controls.

Temple of Enlightenment

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

Selfless Squire

Flash
When Selfless Squire enters the battlefield, prevent all damage that would be dealt to you this turn.
Whenever damage that would be dealt to you is prevented, put that many +1/+1 counters on Selfless Squire.

Silent Arbiter

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

Loran of the Third Path

Vigilance
When Loran of the Third Path enters the battlefield, destroy up to one target artifact or enchantment.
{T}: You and target opponent each draw a card.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering the battlefield 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.