Negate

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Dovescape

({W/U} can be paid with either {W} or {U}.)
Whenever a player casts a noncreature spell, counter that spell. That player creates X 1/1 white and blue Bird creature tokens with flying, where X is the spell's mana value.

Battlefield Raptor

Kastral, the Windcrested

Flying
Whenever one or more Birds you control deal combat damage to a player, choose one —
• You may put a Bird creature card from your hand or graveyard onto the battlefield with a finality counter on it.
• Put a +1/+1 counter on each Bird you control.
• Draw a card.

Icon of Ancestry

As Icon of Ancestry enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{3}, {T}: Look at the top three cards of your library. You may reveal a creature card of the chosen type from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Skycloud Expanse

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.

Dovin's Veto

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

Mystic Gate

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

Winged Words

This spell costs {1} less to cast if you control a creature with flying.
Draw two cards.

Ishai, Ojutai Dragonspeaker

Flying
Whenever an opponent casts a spell, put a +1/+1 counter on Ishai, Ojutai Dragonspeaker.
Partner (You can have two commanders if both have partner.)

Wing Shards

Target player sacrifices an attacking creature of their choice.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Soulcatchers' Aerie

Whenever a Bird is put into your graveyard from the battlefield, put a feather counter on Soulcatchers' Aerie.
Bird creatures get +1/+1 for each feather counter on Soulcatchers' Aerie.

Counterspell

Jackdaw Savior

Flying
Whenever Jackdaw Savior or another creature you control with flying dies, return another target creature card with lesser mana value from your graveyard to the battlefield.

Reflections of Littjara

As Reflections of Littjara enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)

Curiosity Crafter

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

Reliquary Tower

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

Murmuration

Birds you control get +1/+1 and have vigilance.
At the beginning of your end step, for each spell you've cast this turn, create a 1/2 blue Bird creature token with flying named Storm Crow.

Deluge

Ghostly Prison

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

Aven Mindcensor

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

Thriving Isle

Thriving Isle enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Kangee's Lieutenant

Flying
Whenever Kangee's Lieutenant attacks, attacking creatures with flying get +1/+1 until end of turn.
Encore {5}{W} ({5}{W}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Watcher of the Spheres

Flying
Creature spells with flying you cast cost {1} less to cast.
Whenever another creature you control with flying enters, Watcher of the Spheres gets +1/+1 until end of turn.

Secluded Courtyard

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Soulcatcher

Flying
Whenever a creature with flying dies, put a +1/+1 counter on Soulcatcher.

Prairie Stream

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

Aetherize

Return all attacking creatures to their owner's hand.

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.)

Island

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

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.)

Lilypad Village

{T}: Add {C}.
{T}: Add {U}. Spend this mana only to cast a creature spell.
{U}, {T}: Surveil 2. Activate only if a Bird, Frog, Otter, or Rat entered the battlefield under your control this turn.

Plains

Perch Protection

Gift an extra turn (You may promise an opponent a gift as you cast this spell. If you do, they take an extra turn after this one.)
Create four 2/2 blue Bird creature tokens with flying. If the gift was promised, all permanents you control phase out, and until your next turn, your life total can't change and you gain protection from everything.
Exile Perch Protection.

Irrigated Farmland

({T}: Add {W} or {U}.)
Irrigated Farmland enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Gust of Wind

This spell costs {2} less to cast if you control a creature with flying.
Return target nonland permanent you don't control to its owner's hand.
Draw a card.

Animal Sanctuary

{T}: Add {C}.
{2}, {T}: Put a +1/+1 counter on target Bird, Cat, Dog, Goat, Ox, or Snake.

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

Glacial Fortress

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

Unclaimed Territory

As Unclaimed Territory enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Command Tower

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

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Knightfisher

Flying
Whenever another nontoken Bird you control enters, create a 1/1 blue Fish creature token.

Arcane Signet

Sol Ring

Steel-Plume Marshal

Flying
Whenever Steel-Plume Marshal attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Strix Lookout

Flying, vigilance (Attacking doesn't cause this creature to tap.)
{1}{U}, {T}: Draw a card, then discard a card.

Clinquant Skymage

Flying
Whenever you draw a card, put a +1/+1 counter on this creature.

Rogue's Passage

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

Favorable Winds

Creatures you control with flying get +1/+1.

Long River's Pull

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
Counter target creature spell. If the gift was promised, instead counter target spell.

Propaganda

Banner of Kinship

As this artifact enters, choose a creature type. This artifact enters with a fellowship counter on it for each creature you control of the chosen type.
Creatures you control of the chosen type get +1/+1 for each fellowship counter on this artifact.

Idyllic Beachfront

({T}: Add {W} or {U}.)
Idyllic Beachfront enters tapped.

Lofty Denial

Counter target spell unless its controller pays {1}. If you control a creature with flying, counter that spell unless its controller pays {4} instead.

Aerial Assault

Destroy target tapped creature. You gain 1 life for each creature you control with flying.

Azorius Guildgate

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

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Keeper of the Nine Gales

Flying
{T}, Tap two untapped Birds you control: Return target permanent to its owner's hand.

Mockingbird

Flying
You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

Windbrisk Raptor

Flying
Attacking creatures you control have lifelink.

Seaside Haven

{T}: Add {C}.
{W}{U}, {T}, Sacrifice a Bird: Draw a card.

Floodfarm Verge

{T}: Add {W}.
{T}: Add {U}. Activate only if you control a Plains or an Island.

Kangee, Aerie Keeper

Kicker {X}{2} (You may pay an additional {X}{2} as you cast this spell.)
Flying
When Kangee, Aerie Keeper enters, if it was kicked, put X feather counters on it.
Other Bird creatures get +1/+1 for each feather counter on Kangee, Aerie Keeper.

Rally of Wings

Untap all creatures you control. Creatures you control with flying get +2/+2 until end of turn.

Teshar, Ancestor's Apostle

Flying
Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)

Cartographer's Hawk

Flying
When Cartographer's Hawk deals combat damage to a player who controls more lands than you, return it to its owner's hand. If you do, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle.

Plumecreed Escort

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

Dazzling Denial

Counter target spell unless its controller pays {2}. If you control a Bird, counter that spell unless its controller pays {4} instead.

Harrier Strix

Flying
When Harrier Strix enters, tap target permanent.
{2}{U}: Draw a card, then discard a card.

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

Get Out

Choose one —
• Counter target creature or enchantment spell.
• Return one or two target creatures and/or enchantments you own to your hand.

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Azorius Signet

Cloudchaser Kestrel

Flying
When Cloudchaser Kestrel enters, destroy target enchantment.
{W}: Target permanent becomes white until end of turn.

Kangee, Sky Warden

Flying, vigilance
Whenever Kangee, Sky Warden attacks, attacking creatures with flying get +2/+0 until end of turn.
Whenever Kangee blocks, blocking creatures with flying get +0/+2 until end of turn.

Thriving Heath

Thriving Heath enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Azorius Chancery

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

Dawn's Truce

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
You and permanents you control gain hexproof until end of turn. If the gift was promised, permanents you control also gain indestructible until end of turn.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

Skyskipper Duo

Flying
When Skyskipper Duo enters, exile up to one other target creature you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

Azorius Keyrune

{T}: Add {W} or {U}.
{W}{U}: Azorius Keyrune becomes a 2/2 white and blue Bird artifact creature with flying until end of turn.

Thrummingbird

Flying
Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Judge's Familiar

Flying
Sacrifice Judge's Familiar: Counter target instant or sorcery spell unless its controller pays {1}.

Lifecreed Duo

Flying
Whenever another creature you control enters, you gain 1 life.

Shrike Force

Warden of Evos Isle

Flying
Creature spells with flying you cast cost {1} less to cast.

Plumecreed Mentor

Flying
Whenever Plumecreed Mentor or another creature you control with flying enters, put a +1/+1 counter on target creature you control without flying.

Temple of Enlightenment

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 {W} or {U}.