Kiri-Onna

When this creature enters, return target creature to its owner's hand.
Whenever you cast a Spirit or Arcane spell, you may return this creature to its owner's hand.

He Who Hungers

Flying
{1}, Sacrifice a Spirit: Target opponent reveals their hand. You choose a card from it. That player discards that card. Activate only as a sorcery.
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Loam Dweller

Whenever you cast a Spirit or Arcane spell, you may put a land card from your hand onto the battlefield tapped.

Celestial Kirin

Flying
Whenever you cast a Spirit or Arcane spell, destroy all permanents with that spell's mana value.

Floating-Dream Zubera

When this creature dies, draw a card for each Zubera that died this turn.

Cloudhoof Kirin

Flying
Whenever you cast a Spirit or Arcane spell, you may have target player mill X cards, where X is that spell's mana value.

Kodama of the Center Tree

Kodama of the Center Tree's power and toughness are each equal to the number of Spirits you control.
Kodama of the Center Tree has soulshift X, where X is the number of Spirits you control. (When this creature dies, you may return target Spirit card with mana value X or less from your graveyard to your hand.)

Dreamcatcher

Whenever you cast a Spirit or Arcane spell, you may sacrifice this creature. If you do, draw a card.

O-Kagachi, Vengeful Kami

Flying, trample
Whenever O-Kagachi, Vengeful Kami deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

Infernal Kirin

Flying
Whenever you cast a Spirit or Arcane spell, target player reveals their hand and discards all cards with that spell's mana value.

Emissary of Despair

Flying
Whenever this creature deals combat damage to a player, that player loses 1 life for each artifact they control.

Kagemaro, First to Suffer

Kagemaro's power and toughness are each equal to the number of cards in your hand.
{B}, Sacrifice Kagemaro: All creatures get -X/-X until end of turn, where X is the number of cards in your hand.

Haru-Onna

When this creature enters, draw a card.
Whenever you cast a Spirit or Arcane spell, you may return this creature to its owner's hand.

Briarknit Kami

Whenever you cast a Spirit or Arcane spell, put a +1/+1 counter on target creature.

Lifespinner

{T}, Sacrifice three Spirits: Search your library for a legendary Spirit permanent card, put it onto the battlefield, then shuffle.

Kyoki, Sanity's Eclipse

Whenever you cast a Spirit or Arcane spell, target opponent exiles a card from their hand.

Kami of Ancient Law

Sacrifice this creature: Destroy target enchantment.

Keiga, the Tide Star

Flying
When Keiga dies, gain control of target creature.

Mannichi, the Fevered Dream

{1}{R}: Switch each creature's power and toughness until end of turn.

Elder Pine of Jukai

Whenever you cast a Spirit or Arcane spell, reveal the top three cards of your library. Put all land cards revealed this way into your hand and the rest on the bottom of your library in any order.
Soulshift 2 (When this creature dies, you may return target Spirit card with mana value 2 or less from your graveyard to your hand.)

Myojin of Life's Web

Myojin of Life's Web enters with a divinity counter on it if you cast it from your hand.
Myojin of Life's Web has indestructible as long as it has a divinity counter on it.
Remove a divinity counter from Myojin of Life's Web: Put any number of creature cards from your hand onto the battlefield.

Horizon Seed

Whenever you cast a Spirit or Arcane spell, regenerate target creature.

Glitterfang

Haste
At the beginning of the end step, return this creature to its owner's hand.

Harbinger of Spring

Protection from non-Spirit creatures
Soulshift 4 (When this creature dies, you may return target Spirit card with mana value 4 or less from your graveyard to your hand.)

Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Kodama of the South Tree

Whenever you cast a Spirit or Arcane spell, each other creature you control gets +1/+1 and gains trample until end of turn.

Hearth Kami

{X}, Sacrifice this creature: Destroy target artifact with mana value X.

Earthshaker

Whenever you cast a Spirit or Arcane spell, this creature deals 2 damage to each creature without flying.