Call a Surprise Witness

Return target creature card with mana value 3 or less from your graveyard to the battlefield. Put a flying counter on it. It's a Spirit in addition to its other types.

Clarion Spirit

Whenever you cast your second spell each turn, create a 1/1 white Spirit creature token with flying.

Nikko-Onna

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

Thalisse, Reverent Medium

At the beginning of each end step, create X 1/1 white Spirit creature tokens with flying, where X is the number of tokens you created this turn.

King of the Oathbreakers

Flying
Whenever King of the Oathbreakers or another Spirit you control becomes the target of a spell, it phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)
Whenever King of the Oathbreakers or another Spirit you control phases in, create a tapped 1/1 white Spirit creature token with flying.

Haunted Library

Whenever a creature an opponent controls dies, you may pay {1}. If you do, create a 1/1 white Spirit creature token with flying.

Spectral Procession

Create three 1/1 white Spirit creature tokens with flying.

Baku Altar

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

Mausoleum Guard

When this creature dies, create two 1/1 white Spirit creature tokens with flying.

Rend Flesh

Adaptive Automaton

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Kyoki, Sanity's Eclipse

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

Indebted Spirit

Bestow {2}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Afterlife 1 (When this permanent is put into a graveyard from the battlefield, create a 1/1 white and black Spirit creature token with flying.)
Enchanted creature gets +1/+1 and has afterlife 1.

Archaeomancer's Map

When this artifact enters, search your library for up to two basic Plains cards, reveal them, put them into your hand, then shuffle.
Whenever a land an opponent controls enters, if that player controls more lands than you, you may put a land card from your hand onto the battlefield.

Not Forgotten

Put target card from a graveyard on your choice of the top or bottom of its owner's library. Create a 1/1 white Spirit creature token with flying.

Orzhov Enforcer

Deathtouch
Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Soul Search

Target opponent reveals their hand. You choose a nonland card from it. Exile that card. If the card's mana value is 1 or less, create a 1/1 white and black Spirit creature token with flying.

Sandsteppe Outcast

When this creature enters, choose one —
• Put a +1/+1 counter on this creature.
• Create a 1/1 white Spirit creature token with flying.

Luminous Angel

Flying
At the beginning of your upkeep, you may create a 1/1 white Spirit creature token with flying.

Descendant of Storms

Whenever this creature attacks, you may pay {1}{W}. If you do, it endures 1. (Put a +1/+1 counter on it or create a 1/1 white Spirit creature token.)

Gods' Eye, Gate to the Reikai

{T}: Add {C}.
When Gods' Eye is put into a graveyard from the battlefield, create a 1/1 colorless Spirit creature token.

Valor of the Worthy

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature leaves the battlefield, create a 1/1 white Spirit creature token with flying.

Anafenza, Unyielding Lineage

Flash
First strike
Whenever another nontoken creature you control dies, Anafenza endures 2. (Put two +1/+1 counters on it or create a 2/2 white Spirit creature token.)

Seraph of the Scales

Flying
{W}: This creature gains vigilance until end of turn.
{B}: This creature gains deathtouch until end of turn.
Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

Phoenix Down

{1}{W}, {T}, Exile this artifact: Choose one —
• Return target creature card with mana value 4 or less from your graveyard to the battlefield tapped.
• Exile target Skeleton, Spirit, or Zombie.

Angel of Flight Alabaster

Flying
At the beginning of your upkeep, return target Spirit card from your graveyard to your hand.

Imperious Oligarch

Vigilance
Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

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.

Katilda's Rising Dawn

Enchant creature
Enchanted creature has flying, lifelink, and protection from Vampires, and it gets +X/+X, where X is the number of permanents you control that are Spirits and/or enchantments.
If Katilda's Rising Dawn would be put into a graveyard from anywhere, exile it instead.

Katilda, Dawnhart Martyr

Flying, lifelink, protection from Vampires
Katilda's power and toughness are each equal to the number of permanents you control that are Spirits and/or enchantments.
Disturb {3}{W}{W} (You may cast this card from your graveyard transformed for its disturb cost.)

Katilda, Dawnhart Martyr // Katilda's Rising Dawn

Midnight Haunting

Create two 1/1 white Spirit creature tokens with flying.

Field of Souls

Whenever a nontoken creature is put into your graveyard from the battlefield, create a 1/1 white Spirit creature token with flying.

Kami of the Waning Moon

Flying
Whenever you cast a Spirit or Arcane spell, target creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Andúril, Flame of the West

Equipped creature gets +3/+1.
Whenever equipped creature attacks, create two tapped 1/1 white Spirit creature tokens with flying. If that creature is legendary, instead create two of those tokens that are tapped and attacking.
Equip {2}

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.

Gallows Warden

Flying
Other Spirit creatures you control get +0/+1.

Blessed Defiance

Target creature you control gets +2/+0 and gains lifelink until end of turn. When that creature dies this turn, create a 1/1 white Spirit creature token with flying.

Gibbering Kami

Flying
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Orzhov Racketeers

Whenever this creature deals combat damage to a player, that player discards a card.
Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

Go-Shintai of Shared Purpose

Vigilance
At the beginning of your end step, you may pay {1}. If you do, create a 1/1 colorless Spirit creature token for each Shrine you control.

Gathering Stone

As this artifact enters, choose a creature type.
Spells you cast of the chosen type cost {1} less to cast.
When this artifact enters and at the beginning of your upkeep, look at the top card of your library. If it's a card of the chosen type, you may reveal it and put it into your hand. If you don't put the card into your hand, you may put it into your graveyard.

Long-Forgotten Gohei

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

Lingering Souls

Create two 1/1 white Spirit creature tokens with flying.
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Realm of Koh

This land enters tapped unless you control a basic land.
{T}: Add {B}.
{3}{B}, {T}: Create a 1/1 colorless Spirit creature token with "This token can't block or be blocked by non-Spirit creatures."

Spirit Cairn

Whenever a player discards a card, you may pay {W}. If you do, create a 1/1 white Spirit creature token with flying.

Priest of the Blessed Graf

At the beginning of your end step, create X 1/1 white Spirit creature tokens with flying, where X is the number of opponents who control more lands than you.

Ethereal Absolution

Creatures you control get +1/+1.
Creatures your opponents control get -1/-1.
{2}{W}{B}: Exile target card from an opponent's graveyard. If it was a creature card, you create a 1/1 white and black Spirit creature token with flying.

Twilight Drover

Whenever a creature token leaves the battlefield, put a +1/+1 counter on this creature.
{2}{W}, Remove a +1/+1 counter from this creature: Create two 1/1 white Spirit creature tokens with flying.

Architect of Restoration

Vigilance
Whenever this creature attacks or blocks, create a 1/1 colorless Spirit creature token.

The Restoration of Eiganjo

(As this Saga enters and after your draw step, add a lore counter.)
I — Search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
II — You may discard a card. When you do, return target permanent card with mana value 2 or less from your graveyard to the battlefield tapped.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Restoration of Eiganjo // Architect of Restoration

Doomed Traveler

When this creature dies, create a 1/1 white Spirit creature token with flying.

Afterlife Insurance

Creatures you control gain afterlife 1 until end of turn. Draw a card. (When a creature with afterlife 1 dies, create a 1/1 white and black Spirit creature token with flying.)

Deathknell Kami

Flying
{2}: This creature gets +1/+1 until end of turn. Sacrifice it at the beginning of the next end step.
Soulshift 1 (When this creature dies, you may return target Spirit card with mana value 1 or less from your graveyard to your hand.)

Sandskitter Outrider

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, it endures 2. (Put two +1/+1 counters on it or create a 2/2 white Spirit creature token.)

Alharu, Solemn Ritualist

When Alharu enters, put a +1/+1 counter on each of up to two other target creatures.
Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Spirit creature token with flying.
Partner (You can have two commanders if both have partner.)

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.)

Fortress Kin-Guard

When this creature enters, it endures 1. (Put a +1/+1 counter on it or create a 1/1 white Spirit creature token.)

Thalia's Geistcaller

Lifelink
Whenever you cast a spell from your graveyard, create a 1/1 white Spirit creature token with flying.
Sacrifice a Spirit: This creature gains indestructible until end of turn.

Hanged Executioner

Flying
When this creature enters, create a 1/1 white Spirit creature token with flying.
{3}{W}, Exile this creature: Exile target creature.

Ministrant of Obligation

Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

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.