Wings of the Cosmos

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

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.

Illusions of Grandeur

Cumulative upkeep {2} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When Illusions of Grandeur enters, you gain 20 life.
When Illusions of Grandeur leaves the battlefield, you lose 20 life.

Zephyr Falcon

Arcane Signet

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

School of Piranha

At the beginning of your upkeep, sacrifice School of Piranha unless you pay {1}{U}.

Breath of Dreams

Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Green creatures have "Cumulative upkeep {1}."

Silver Raven

Flying
When Silver Raven enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Spindrift Drake

Flying
At the beginning of your upkeep, sacrifice Spindrift Drake unless you pay {U}.

Stormscape Familiar

Flying
White spells and black spells you cast cost {1} less to cast.

Mind Harness

Enchant red or green creature
Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
You control enchanted creature.

Sky Theater Strix

Flying
Whenever you cast a noncreature spell, Sky Theater Strix gets +1/+0 until end of turn.

Enchantment Alteration

Attach target Aura attached to a creature or land to another permanent of that type.

Soulcatcher

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

Falcon Abomination

Flying
When Falcon Abomination enters, create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

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.)

Pacifism

Enchant creature
Enchanted creature can't attack or block.

Sustainer of the Realm

Flying
Whenever Sustainer of the Realm blocks, it gets +0/+2 until end of turn.

Relearn

Return target instant or sorcery card from your graveyard to your hand.

Bay Falcon

Aven Gagglemaster

Flying
When Aven Gagglemaster enters, you gain 2 life for each creature you control with flying.

Griffin Sentinel

Flying
Vigilance (Attacking doesn't cause this creature to tap.)

Seacoast Drake

Warded Battlements

Defender (This creature can't attack.)
Attacking creatures you control get +1/+0.

Bone to Ash

Counter target creature spell.
Draw a card.

Ghostly Wings

Enchant creature
Enchanted creature gets +1/+1 and has flying.
Discard a card: Return enchanted creature to its owner's hand.

Airborne Aid

Draw a card for each Bird on the battlefield.

Frost Trickster

Flying
When Frost Trickster enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Inniaz, the Gale Force

Flying
{2}{W/U}: Attacking creatures with flying get +1/+1 until end of turn. ({W/U} can be paid with either {W} or {U}.)
Whenever three or more creatures you control with flying attack, each player gains control of a nonland permanent of your choice controlled by the player to their right.

Adarkar Unicorn

{T}: Add {U} or {C}{U}. Spend this mana only to pay cumulative upkeep costs.

Psychic Barrier

Counter target creature spell. Its controller loses 1 life.

Rebound

Change the target of target spell that targets only a player. The new target must be a player.

Illusionary Forces

Flying
Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Plains

Strip Bare

Destroy all Auras and Equipment attached to target creature.

Battlefield Raptor

Keeper of the Nine Gales

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

Agoraphobia

Enchant creature
Enchanted creature gets -5/-0.
{2}{U}: Return Agoraphobia to its owner's hand.

Flicker of Fate

Exile target creature or enchantment, then return it to the battlefield under its owner's control.

Condescend

Counter target spell unless its controller pays {X}. Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Jötun Owl Keeper

Cumulative upkeep {W} or {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
When Jötun Owl Keeper dies, create a 1/1 white Bird creature token with flying for each age counter on it.

Sol Ring

Phantom Monster

Celestial Gatekeeper

Flying
When Celestial Gatekeeper dies, exile it, then return up to two target Bird and/or Cleric permanent cards from your graveyard to the battlefield.

Combat Professor

Flying
At the beginning of combat on your turn, target creature you control gets +1/+0 and gains vigilance until end of turn.

Halls of Mist

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Creatures that attacked during their controller's last turn can't attack.

Forced Worship

Enchant creature
Enchanted creature can't attack.
{2}{W}: Return Forced Worship to its owner's hand.

Tempest Drake

Numbing Dose

Enchant artifact or creature
Enchanted permanent doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted permanent's controller, that player loses 1 life.

Riot Gear

Equipped creature gets +1/+2.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Ornitharch

Flying
Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)
When Ornitharch enters, if tribute wasn't paid, create two 1/1 white Bird creature tokens with flying.

Befuddle

Target creature gets -4/-0 until end of turn.
Draw a card.

Leonin Skyhunter

Seraph of Dawn

Tranquil Cove

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

Cloudfin Raptor

Flying
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.)

Prismatic Boon

Choose a color. X target creatures gain protection from the chosen color until end of turn.

Dreams of the Dead

{1}{U}: Return target white or black creature card from your graveyard to the battlefield. That creature gains "Cumulative upkeep {2}." If the creature would leave the battlefield, exile it instead of putting it anywhere else. (At the beginning of its controller's upkeep, that player puts an age counter on it, then sacrifices it unless they pay its upkeep cost for each age counter on it.)

Sparring Regimen

When Sparring Regimen enters, learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)
Whenever you attack, put a +1/+1 counter on target attacking creature and untap it.

Thieving Magpie

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Thieving Magpie deals damage to an opponent, draw a card.

Sage Owl

Flying
When Sage Owl enters, look at the top four cards of your library, then put them back in any order.

Zephyr Spirit

When Zephyr Spirit blocks, return it to its owner's hand.

Perplexing Chimera

Whenever an opponent casts a spell, you may exchange control of Perplexing Chimera and that spell. If you do, you may choose new targets for the spell. (If the spell becomes a permanent, you control that permanent.)

Island

Azorius Signet

Angelic Curator

Condemn

Put target attacking creature on the bottom of its owner's library. Its controller gains life equal to its toughness.

Battle Screech

Create two 1/1 white Bird creature tokens with flying.
Flashback—Tap three untapped white creatures you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Courier Griffin

Flying
When Courier Griffin enters, you gain 2 life.

Creature Bond

Enchant creature
When enchanted creature dies, Creature Bond deals damage equal to that creature's toughness to the creature's controller.

Illusionary Wall

Defender, flying, first strike
Cumulative upkeep {U} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)