Helm of the Host

At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary. That token gains haste.
Equip {5}

Storm Herd

Create X 1/1 white Pegasus creature tokens with flying, where X is your life total.

Sphinx's Revelation

Wingmate Roc

Flying
Raid — When this creature enters, if you attacked this turn, create a 3/4 white Bird creature token with flying.
Whenever this creature attacks, you gain 1 life for each attacking creature.

Terramorphic Expanse

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

Winged Words

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

Floodfarm Verge

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

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Rally of Wings

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

Curiosity Crafter

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

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Azorius Keyrune

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

Azorius Locket

{T}: Add {W} or {U}.
{W/U}{W/U}{W/U}{W/U}, {T}, Sacrifice this artifact: Draw two cards.

Archangel of Tithes

Flying
As long as this creature is untapped, creatures can't attack you or planeswalkers you control unless their controller pays {1} for each of those creatures.
As long as this creature is attacking, creatures can't block unless their controller pays {1} for each of those creatures.

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.

Absorb

Pearl Medallion

White spells you cast cost {1} less to cast.

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.

Jubilant Skybonder

Flying
Creatures you control with flying have "Spells your opponents cast that target this creature cost {2} more to cast."

Talisman of Progress

{T}: Add {C}.
{T}: Add {W} or {U}. This artifact deals 1 damage to you.

Dazzling Denial

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

Empyrean Eagle

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

Arcane Signet

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Archon of Redemption

Flying
Whenever this creature or another creature you control with flying enters, you may gain life equal to that creature's power.

Holy Cow

Flash
Flying
When this creature enters, you gain 2 life and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Tide Skimmer

Flying
Whenever you attack with two or more creatures with flying, draw a card.

Negate

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.

Thraben Watcher

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

Skycloud Expanse

Seachrome Coast

This land enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Commander's Sphere

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

Command Tower

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.)

Jackdaw Savior

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

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Aven Gagglemaster

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

Exotic Orchard

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

Aetherize

Return all attacking creatures to their owner's hand.

Plains

Island

Prairie Stream

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

Dauntless Aven

Flying
Whenever this creature attacks, untap target creature you control.

Disenchant

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.)

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Sol Ring

The Raven's Warning

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Create a 1/1 blue Bird creature token with flying. You gain 2 life.
II — Whenever one or more creatures you control with flying deal combat damage to a player this turn, look at that player's hand and draw a card.
III — You may put a card you own from outside the game on top of your library.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. This land deals 1 damage to you.

Skycat Sovereign

Flying
This creature 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.

Steel-Plume Marshal

Flying
Whenever this creature attacks, other attacking creatures you control with flying get +2/+2 until end of turn.

Ancient Gold Dragon

Flying
Whenever this creature deals combat damage to a player, roll a d20. You create a number of 1/1 blue Faerie Dragon creature tokens with flying equal to the result.

Ever-Watching Threshold

Whenever an opponent attacks, if they attacked you and/or a planeswalker you control, draw a card.

Reliquary Tower

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

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Thought Vessel

Glacial Fortress

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

Pull from Tomorrow

Lifecreed Duo

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

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.

Warden of Evos Isle

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

True Conviction

Creatures you control have double strike and lifelink.

Inspiring Overseer

Flying
When this creature enters, you gain 1 life and draw a card.

Evolving Wilds

Kangee, Sky Warden

Flying, vigilance
Whenever Kangee 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.

Favorable Winds

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

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.

Counterspell

Gravitational Shift

Creatures with flying get +2/+0.
Creatures without flying get -2/-0.

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Deluge

Dovin's Veto

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

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Sejiri Refuge

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