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.)

Revoke Existence

Kor Skyfisher

Flying
When this creature enters, return a permanent you control to its owner's hand.

Lone Missionary

When this creature enters, you gain 4 life.

Squadron Hawk

Flying
When this creature enters, you may search your library for up to three cards named Squadron Hawk, reveal them, put them into your hand, then shuffle.

Idyllic Grange

({T}: Add {W}.)
This land enters tapped unless you control three or more other Plains.
When this land enters untapped, put a +1/+1 counter on target creature you control.

Raffine's Informant

When this creature enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Thraben Inspector

When this creature enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Luminous Phantom

Flying
Whenever another creature you control leaves the battlefield, you gain 1 life.
If Luminous Phantom would be put into a graveyard from anywhere, exile it instead.

Lunarch Veteran

Whenever another creature you control enters, you gain 1 life.
Disturb {1}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Lunarch Veteran // Luminous Phantom

Eagles of the North

Flying
When this creature enters, creatures you control get +1/+0 and gain first strike until end of turn.
Plainscycling {1} ({1}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Prismatic Strands

Prevent all damage that sources of the color of your choice would deal this turn.
Flashback—Tap an untapped white creature you control. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Standard Bearer

While an opponent is choosing targets as part of casting a spell they control or activating an ability they control, that player must choose at least one Flagbearer on the battlefield if able.

Summon: Choco/Mog

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I, II, III, IV — Stampede! — Other creatures you control get +1/+0 until end of turn.

Plains

Outlaw Medic

Lifelink
When this creature dies, draw a card.

Guardians' Pledge

White creatures you control get +2/+2 until end of turn.

Greatsword of Tyr

Whenever equipped creature attacks, put a +1/+1 counter on it and tap up to one target creature defending player controls.
Equip {W} ({W}: Attach to target creature you control. Equip only as a sorcery.)

Journey to Nowhere

When this enchantment enters, exile target creature.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Thraben Charm

Choose one —
• Thraben Charm deals damage equal to twice the number of creatures you control to target creature.
• Destroy target enchantment.
• Exile any number of target players' graveyards.