Petalmane Baku

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Petalmane Baku.
{1}, Remove X ki counters from Petalmane Baku: Add X mana of any one color.

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.)

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.

Long-Forgotten Gohei

Arcane spells you cast cost {1} less to cast.
Spirit creatures you control get +1/+1.

Forest

Devouring Greed

As an additional cost to cast this spell, you may sacrifice any number of Spirits.
Target player loses 2 life plus 2 life for each Spirit sacrificed this way. You gain that much life.

Celestial Kirin

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

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.

Ichiga, Who Topples Oaks

Trample
Remove a ki counter from Ichiga, Who Topples Oaks: Target creature gets +2/+2 until end of turn.

Budoka Pupil

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Budoka Pupil.
At the beginning of the end step, if there are two or more ki counters on Budoka Pupil, you may flip it.

Budoka Pupil // Ichiga, Who Topples Oaks

Waxmane Baku

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Waxmane Baku.
{1}, Remove X ki counters from Waxmane Baku: Tap X target creatures.

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.

Plains

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.

Hana Kami

{1}{G}, Sacrifice Hana Kami: Return target Arcane card from your graveyard to your hand.

Soulless Revival

Return target creature card from your graveyard to your hand.
Splice onto Arcane {1}{B} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Swamp

Baku Altar

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Baku Altar.
{2}, {T}, Remove a ki counter from Baku Altar: Create a 1/1 colorless Spirit creature token.

Choice of Damnations

Target opponent chooses a number. You may have that player lose that much life. If you don't, that player sacrifices all but that many permanents of their choice.

Rend Flesh

Kaiso, Memory of Loyalty

Flying
Remove a ki counter from Kaiso, Memory of Loyalty: Prevent all damage that would be dealt to target creature this turn.

Faithful Squire

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Faithful Squire.
At the beginning of the end step, if there are two or more ki counters on Faithful Squire, you may flip it.

Faithful Squire // Kaiso, Memory of Loyalty

Bounteous Kirin

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

Wear Away

Destroy target artifact or enchantment.
Splice onto Arcane {3}{G} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Scarmaker

Remove a ki counter from Scarmaker: Target creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Hired Muscle

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Hired Muscle.
At the beginning of the end step, if there are two or more ki counters on Hired Muscle, you may flip it.

Hired Muscle // Scarmaker

Oyobi, Who Split the Heavens

Flying
Whenever you cast a Spirit or Arcane spell, create a 3/3 white Spirit creature token with flying.

Loam Dweller

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

Thief of Hope

Whenever you cast a Spirit or Arcane spell, target opponent loses 1 life and you gain 1 life.
Soulshift 2 (When this creature dies, you may return target Spirit card with mana value 2 or less from your graveyard to your hand.)

Myrkul, Lord of Bones

As long as your life total is less than or equal to half your starting life total, Myrkul, Lord of Bones has indestructible.
Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that card, except it's an enchantment and loses all other card types.

Skullmane Baku

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Skullmane Baku.
{1}, {T}, Remove X ki counters from Skullmane Baku: Target creature gets -X/-X until end of turn.

Ugin's Conjurant

Ugin's Conjurant enters with X +1/+1 counters on it.
If damage would be dealt to Ugin's Conjurant while it has a +1/+1 counter on it, prevent that damage and remove that many +1/+1 counters from Ugin's Conjurant.

Kyoki, Sanity's Eclipse

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