Kemuri-Onna

When Kemuri-Onna enters, target player discards a card.
Whenever you cast a Spirit or Arcane spell, you may return Kemuri-Onna to its owner's hand.

Blinking Spirit

{0}: Return Blinking Spirit to its owner's hand.

Iname as One

When Iname as One enters, if you cast it from your hand, you may search your library for a Spirit permanent card, put it onto the battlefield, then shuffle.
When Iname as One dies, you may exile it. If you do, return target Spirit permanent card from your graveyard to the battlefield.

Haru-Onna

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

Yuki-Onna

When Yuki-Onna enters, destroy target artifact.
Whenever you cast a Spirit or Arcane spell, you may return Yuki-Onna to its owner's hand.

Masumaro, First to Live

Masumaro, First to Live's power and toughness are each equal to twice the number of cards in your hand.

Nikko-Onna

When Nikko-Onna enters, destroy target enchantment.
Whenever you cast a Spirit or Arcane spell, you may return Nikko-Onna to its owner's hand.

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.

Skyfire Kirin

Flying
Whenever you cast a Spirit or Arcane spell, you may gain control of target creature with that spell's mana value until end of turn.

Bounteous Kirin

Flying
Whenever you cast a Spirit or Arcane spell, you may gain life equal to that spell's mana value.

Kagemaro, First to Suffer

Kagemaro, First to Suffer'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.

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.

Kagemaro's Clutch

Enchant creature
Enchanted creature gets -X/-X, where X is the number of cards in your hand.

Kiyomaro, First to Stand

Kiyomaro, First to Stand's power and toughness are each equal to the number of cards in your hand.
As long as you have four or more cards in hand, Kiyomaro has vigilance.
Whenever Kiyomaro deals damage, if you have seven or more cards in hand, you gain 7 life.