Momo, Friendly Flier

Flying
The first non-Lemur creature spell with flying you cast during each of your turns costs {1} less to cast.
Whenever another creature you control with flying enters, Momo gets +1/+1 until end of turn.

Cosmogrand Zenith

Whenever you cast your second spell each turn, choose one —
• Create two 1/1 white Human Soldier creature tokens.
• Put a +1/+1 counter on each creature you control.

Avatar Kuruk

Whenever you cast a spell, create a 1/1 colorless Spirit creature token with "This token can't block or be blocked by non-Spirit creatures."
Exhaust — Waterbend {20}: Take an extra turn after this one. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}. Activate each exhaust ability only once.)

The Legend of Kuruk

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Scry 2, then draw a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Legend of Kuruk // Avatar Kuruk

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Day of Judgment

Riverpyre Verge

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

Steam Vents

({T}: Add {U} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Spider-Sense

Web-slinging {U} (You may cast this spell for {U} if you also return a tapped creature you control to its owner's hand.)
Counter target instant spell, sorcery spell, or triggered ability.

Sunbillow Verge

{T}: Add {W}.
{T}: Add {R}. Activate only if you control a Mountain or a Plains.

Nova Hellkite

Flying, haste
When this creature enters, it deals 1 damage to target creature an opponent controls.
Warp {2}{R} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Coil and Catch

Draw three cards, then discard a card. (Then shuffle this card into its owner's library.)

Marang River Regent

Flying
When this creature enters, return up to two other target nonland permanents to their owners' hands.

Marang River Regent // Coil and Catch

Starfield Shepherd

Flying
When this creature enters, search your library for a basic Plains card or a creature card with mana value 1 or less, reveal it, put it into your hand, then shuffle.
Warp {1}{W} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Curious Farm Animals

When this creature dies, you gain 3 life.
{2}, Sacrifice this creature: Destroy up to one target artifact or enchantment.

Plains

Sacred Foundry

({T}: Add {R} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Spell Snare

Get Lost

Destroy target creature, enchantment, or planeswalker. Its controller creates two Map tokens. (They're artifacts with "{1}, {T}, Sacrifice this token: Target creature you control explores. Activate only as a sorcery.")

Airbender Ascension

When this enchantment enters, airbend up to one target creature.
Whenever a creature you control enters, put a quest counter on this enchantment.
At the beginning of your end step, if this enchantment has four or more quest counters on it, exile up to one target creature you control, then return it to the battlefield under its owner's control.

Ghost-Spider

Flying, vigilance, haste
Whenever you play a land from exile or cast a spell from exile, put a +1/+1 counter on Ghost-Spider.
Remove two counters from Ghost-Spider: Exile the top card of your library. You may play that card this turn.

Gwen Stacy

When Gwen Stacy enters, exile the top card of your library. You may play that card for as long as you control this creature.
{2}{U}{R}{W}: Transform Gwen Stacy. Activate only as a sorcery.

Gwen Stacy // Ghost-Spider

Seam Rip

When this enchantment enters, exile target nonland permanent an opponent controls with mana value 2 or less until this enchantment leaves the battlefield.

Requisition Raid

Spree (Choose one or more additional costs.)
+ {1} — Destroy target artifact.
+ {1} — Destroy target enchantment.
+ {1} — Put a +1/+1 counter on each creature target player controls.

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

The Unagi of Kyoshi Island

Flash
Ward—Waterbend {4}. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}. They can tap their artifacts and creatures to help. Each one pays for {1}.)
Whenever an opponent draws their second card each turn, you draw two cards.

Go Ninja Go

Choose one or both —
• Exile target creature you control, then return it to the battlefield under its owner's control.
• Go Ninja Go deals damage equal to the greatest power among creatures you control to target creature an opponent controls.

Kutzil's Flanker

Flash
When this creature enters, choose one —
• Put a +1/+1 counter on this creature for each creature that left the battlefield under your control this turn.
• You gain 2 life and scry 2.
• Exile target player's graveyard.

Quantum Riddler

Flying
When this creature enters, draw a card.
As long as you have one or fewer cards in hand, if you would draw one or more cards, you draw that many cards plus one instead.
Warp {1}{U}

Ashling, Rimebound

Whenever this creature transforms into Ashling, Rimebound and at the beginning of your first main phase, add two mana of any one color. Spend this mana only to cast spells with mana value 4 or greater.
At the beginning of your first main phase, you may pay {R}. If you do, transform Ashling.

Ashling, Rekindled

Whenever this creature enters or transforms into Ashling, Rekindled, you may discard a card. If you do, draw a card.
At the beginning of your first main phase, you may pay {U}. If you do, transform Ashling.

Ashling, Rekindled // Ashling, Rimebound

Shiko, Paragon of the Way

Flying, vigilance
When Shiko enters, exile target nonland card with mana value 3 or less from your graveyard. Copy it, then you may cast the copy without paying its mana cost. (A copy of a permanent spell becomes a token.)