Cenn's Heir

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

Ballyrush Banneret

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

Knight of Meadowgrain

First strike
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

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.

Plains

Figure of Destiny

{R/W}: Figure of Destiny becomes a Kithkin Spirit with base power and toughness 2/2.
{R/W}{R/W}{R/W}: If Figure of Destiny is a Spirit, it becomes a Kithkin Spirit Warrior with base power and toughness 4/4.
{R/W}{R/W}{R/W}{R/W}{R/W}{R/W}: If Figure of Destiny is a Warrior, it becomes a Kithkin Spirit Warrior Avatar with base power and toughness 8/8, flying, and first strike.

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.

Surge of Thoughtweft

Creatures you control get +1/+1 until end of turn. If you control a Kithkin, draw a card.

Patrol Signaler

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

Galepowder Mage

Flying
Whenever Galepowder Mage attacks, exile another target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Silkwrap

When Silkwrap enters, exile target creature with mana value 3 or less an opponent controls until Silkwrap leaves the battlefield. (That creature returns under its owner's control.)

Wizened Cenn

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

Crib Swap

Changeling (This card is every creature type.)
Exile target creature. Its controller creates a 1/1 colorless Shapeshifter creature token with changeling.

Kithkin Zephyrnaut

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with Kithkin Zephyrnaut, you may reveal it. If you do, Kithkin Zephyrnaut gets +2/+2 and gains flying and vigilance until end of turn.

Preeminent Captain

First strike (This creature deals combat damage before creatures without first strike.)
Whenever Preeminent Captain attacks, you may put a Soldier creature card from your hand onto the battlefield tapped and attacking.

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.

Condemn

Put target attacking creature on the bottom of its owner's library. Its controller gains life equal to its toughness.

Rustic Clachan

As Rustic Clachan enters, you may reveal a Kithkin card from your hand. If you don't, Rustic Clachan enters tapped.
{T}: Add {W}.
Reinforce 1—{1}{W} ({1}{W}, Discard this card: Put a +1/+1 counter on target creature.)

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.)