Selfless Cathar

{1}{W}, Sacrifice Selfless Cathar: Creatures you control get +1/+1 until end of turn.

Plains

Sunlance

Sunlance deals 3 damage to target nonwhite creature.

Ramosian Rally

If you control a Plains, you may tap an untapped creature you control rather than pay this spell's mana cost.
Creatures you control get +1/+1 until end of turn.

Squadron Hawk

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

Cenn's Enlistment

Create two 1/1 white Kithkin Soldier creature tokens.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Gather the Townsfolk

Create two 1/1 white Human creature tokens.
Fateful hour — If you have 5 or less life, create five of those tokens instead.

Soul Warden

Whenever another creature enters, you gain 1 life.

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.)

Triplicate Spirits

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Create three 1/1 white Spirit creature tokens with flying.

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.)