Ballyrush Banneret

Kithkin spells and Soldier spells you cast cost {1} less to cast.

Order of Whiteclay

{1}{W}{W}, {Q}: Return target creature card with mana value 3 or less from your graveyard to the battlefield. ({Q} is the untap symbol.)

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Kithkin Harbinger

When Kithkin Harbinger enters, you may search your library for a Kithkin card, reveal it, then shuffle and put that card on top.

Irregular Cohort

Changeling (This card is every creature type.)
When Irregular Cohort enters, create a 2/2 colorless Shapeshifter creature token with changeling.

Springjack Shepherd

Chroma — When Springjack Shepherd enters, create a 0/1 white Goat creature token for each white mana symbol in the mana costs of permanents you control.

Kinsbaile Borderguard

Kinsbaile Borderguard enters with a +1/+1 counter on it for each other Kithkin you control.
When Kinsbaile Borderguard dies, create a 1/1 white Kithkin Soldier creature token for each counter on it.

Augury Adept

Whenever Augury Adept deals combat damage to a player, reveal the top card of your library and put that card into your hand. You gain life equal to its mana value.

Patrol Signaler

{1}{W}, {Q}: Create a 1/1 white Kithkin Soldier creature token. ({Q} is the untap symbol.)

Kinsbaile Courier

When Kinsbaile Courier enters, put a +1/+1 counter on target creature.
Encore {2}{W} ({2}{W}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Cenn's Heir

Whenever Cenn's Heir attacks, it gets +1/+1 until end of turn for each other attacking Kithkin.

Gaddock Teeg

Noncreature spells with mana value 4 or greater can't be cast.
Noncreature spells with {X} in their mana costs can't be cast.

Derevi, Empyrial Tactician

Flying
When Derevi, Empyrial Tactician enters and whenever a creature you control deals combat damage to a player, you may tap or untap target permanent.
{1}{G}{W}{U}: Put Derevi onto the battlefield from the command zone.

Wizened Cenn

Other Kithkin creatures you control get +1/+1.

Thistledown Liege

Flash
Other white creatures you control get +1/+1.
Other blue creatures you control get +1/+1.

Thoughtweft Trio

First strike, vigilance
Champion a Kithkin (When this enters, sacrifice it unless you exile another Kithkin you control. When this leaves the battlefield, that card returns to the battlefield.)
Thoughtweft Trio can block any number of creatures.

Mistmeadow Witch

{2}{W}{U}: Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Militia's Pride

Whenever a nontoken creature you control attacks, you may pay {W}. If you do, create a 1/1 white Kithkin Soldier creature token that's tapped and attacking.