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.

Skycat Sovereign

Flying
Skycat Sovereign gets +1/+1 for each other creature you control with flying.
{2}{W}{U}: Create a 1/1 white Cat Bird creature token with flying.

Faerie Seer

Flying
When Faerie Seer enters, 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.)

Topplegeist

Flying
When Topplegeist enters, tap target creature an opponent controls.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, tap target creature that player controls.

Serra the Benevolent

+2: Creatures you control with flying get +1/+1 until end of turn.
−3: Create a 4/4 white Angel creature token with flying and vigilance.
−6: You get an emblem with "If you control a creature, damage that would reduce your life total to less than 1 reduces it to 1 instead."

Warden of Evos Isle

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

Hypnotic Siren

Bestow {5}{U}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
You control enchanted creature.
Enchanted creature gets +1/+1 and has flying.

Migratory Route

Create four 1/1 white Bird creature tokens with flying.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Skycloud Expanse

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.

Spirit Bonds

Whenever a nontoken creature you control enters, you may pay {W}. If you do, create a 1/1 white Spirit creature token with flying.
{1}{W}, Sacrifice a Spirit: Target non-Spirit creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Talrand's Invocation

Create two 2/2 blue Drake creature tokens with flying.

Angel of Jubilation

Flying
Other nonblack creatures you control get +1/+1.
Players can't pay life or sacrifice creatures to cast spells or activate abilities.

Thunderclap Wyvern

Flash (You may cast this spell any time you could cast an instant.)
Flying
Other creatures you control with flying get +1/+1.

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.

Favorable Winds

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

Swooping Lookout

Faerie Formation

Flying
{3}{U}: Create a 1/1 blue Faerie creature token with flying. Draw a card.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Plains

Pride of the Clouds

Flying
Pride of the Clouds gets +1/+1 for each other creature on the battlefield with flying.
Forecast — {2}{W}{U}, Reveal Pride of the Clouds from your hand: Create a 1/1 white and blue Bird creature token with flying. (Activate only during your upkeep and only once each turn.)

Hanged Executioner

Flying
When Hanged Executioner enters, create a 1/1 white Spirit creature token with flying.
{3}{W}, Exile Hanged Executioner: Exile target creature.

Sephara, Sky's Blade

You may pay {W} and tap four untapped creatures you control with flying rather than pay this spell's mana cost.
Flying, lifelink
Other creatures you control with flying have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Welcoming Vampire

Flying
Whenever one or more other creatures you control with power 2 or less enter, draw a card. This ability triggers only once each turn.

Prairie Stream

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

Ruin-Lurker Bat

Flying, lifelink
At the beginning of your end step, if you descended this turn, scry 1. (You descended if a permanent card was put into your graveyard from anywhere.)

Healer's Hawk

Rally of Wings

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

Empyrean Eagle

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

Winged Words

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

Judge's Familiar

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

Island

Thraben Watcher

Flying, vigilance
Other nontoken creatures you control get +1/+1 and have vigilance.

Spiketail Drakeling

Flying
Sacrifice Spiketail Drakeling: Counter target spell unless its controller pays {2}.

Spectral Sailor

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

Donal, Herald of Wings

Whenever you cast a nonlegendary creature spell with flying, you may copy it, except the copy is a 1/1 Spirit in addition to its other types. Do this only once each turn. (The copy becomes a token.)