Iname, Death Aspect

When Iname, Death Aspect enters, you may search your library for any number of Spirit cards, put them into your graveyard, then shuffle.

Oyobi, Who Split the Heavens

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

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

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.

Kyoki, Sanity's Eclipse

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

Hikari, Twilight Guardian

Flying
Whenever you cast a Spirit or Arcane spell, you may exile Hikari, Twilight Guardian. If you do, return it to the battlefield under its owner's control at the beginning of the next end step.