Quintorius, Field Historian

Spirits you control get +1/+0.
Whenever one or more cards leave your graveyard, create a 3/2 red and white Spirit creature token.

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.

Oyobi, Who Split the Heavens

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

Blademane Baku

Whenever you cast a Spirit or Arcane spell, you may put a ki counter on Blademane Baku.
{1}, Remove X ki counters from Blademane Baku: For each counter removed, Blademane Baku gets +2/+0 until end of turn.

Azamuki, Treachery Incarnate

Remove a ki counter from Azamuki, Treachery Incarnate: Gain control of target creature until end of turn.

Cunning Bandit

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

Cunning Bandit // Azamuki, Treachery Incarnate

Drogskol Reinforcements

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other Spirits you control have melee.
Prevent all noncombat damage that would be dealt to Spirits you control.

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

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.

Hofri Ghostforge

Spirits you control get +1/+1 and have trample and haste.
Whenever another nontoken creature you control dies, exile it. If you do, create a token that's a copy of that creature, except it's a Spirit in addition to its other types and it has "When this creature leaves the battlefield, return the exiled card to its owner's graveyard."

Kami of Fire's Roar

Whenever you cast a Spirit or Arcane spell, target creature can't block this turn.

Earthshaker

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