Have

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.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Bygone Bishop

Flying
Whenever you cast a creature spell with mana value 3 or less, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Offer Immortality

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Mortify

Scapegoat

As an additional cost to cast this spell, sacrifice a creature.
Return any number of target creatures you control to their owner's hand.

Benevolent Offering

Choose an opponent. You and that player each create three 1/1 white Spirit creature tokens with flying.
Choose an opponent. You gain 2 life for each creature you control and that player gains 2 life for each creature they control.

Karmic Guide

Flying, protection from black
Echo {3}{W}{W} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When this creature enters, return target creature card from your graveyard to the battlefield.

Windborn Muse

Flying
Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Make a Stand

Creatures you control get +1/+0 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Kami of False Hope

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Clarion Spirit

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

Despark

Exile target permanent with mana value 4 or greater.

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.

Swamp

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.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Talisman of Hierarchy

{T}: Add {C}.
{T}: Add {W} or {B}. This artifact deals 1 damage to you.

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Embolden

Prevent the next 4 damage that would be dealt this turn to any number of targets, divided as you choose.
Flashback {1}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Promise of Bunrei

When a creature you control dies, sacrifice this enchantment. If you do, create four 1/1 colorless Spirit creature tokens.

Plains

Removing

Wall of Omens

Defender
When this creature enters, draw a card.

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.

Sol Ring

Kaya, Geist Hunter

+1: Creatures you control gain deathtouch until end of turn. Put a +1/+1 counter on up to one target creature token you control.
−2: Until end of turn, if one or more tokens would be created under your control, twice that many of those tokens are created instead.
−6: Exile all cards from all graveyards, then create a 1/1 white Spirit creature token with flying for each card exiled this way.

Getting

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Oyobi, Who Split the Heavens

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

Sun Titan

Vigilance
Whenever this creature enters or attacks, you may return target permanent card with mana value 3 or less from your graveyard to the battlefield.

Storm of Souls

Return all creature cards from your graveyard to the battlefield. Each of them is a 1/1 Spirit with flying in addition to its other types. Exile Storm of Souls.

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.

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.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Minimus Containment

Enchant nonland permanent
Enchanted permanent is a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color," and it loses all other abilities. (If it was a creature, it's no longer a creature.)

Selfless Spirit

Flying
Sacrifice this creature: Creatures you control gain indestructible until end of turn.

Orzhov Signet

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Kirtar's Wrath

Destroy all creatures. They can't be regenerated.
Threshold — If seven or more cards are in your graveyard, instead destroy all creatures, then create two 1/1 white Spirit creature tokens with flying. Creatures destroyed this way can't be regenerated.

Instruments of War

Flash
As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.

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.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Ronom Unicorn

Sacrifice this creature: Destroy target enchantment.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Angel of Flight Alabaster

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

Remorseful Cleric

Flying
Sacrifice this creature: Exile target player's graveyard.

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Semester's End

Exile any number of target creatures and/or planeswalkers you control. At the beginning of the next end step, return each of them to the battlefield under its owner's control. Each of them enters with an additional +1/+1 counter on it if it's a creature and an additional loyalty counter on it if it's a planeswalker.

Pilgrim of the Ages

When this creature enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
{6}: Return this card from your graveyard to your hand.

Costly Plunder

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards.

Horobi, Death's Wail

Flying
Whenever a creature becomes the target of a spell or ability, destroy that creature.

Call for Unity

Revolt — At the beginning of your end step, if a permanent left the battlefield under your control this turn, put a unity counter on this enchantment.
Creatures you control get +1/+1 for each unity counter on this enchantment.

Orzhov Cluestone

{T}: Add {W} or {B}.
{W}{B}, {T}, Sacrifice this artifact: Draw a card.

Custodi Squire

Flying
Will of the council — When this creature enters, starting with you, each player votes for an artifact, creature, or enchantment card in your graveyard. Return each card with the most votes or tied for most votes to your hand.

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.)

Atrocious Experiment

Target player mills two cards, draws two cards, and loses 2 life. (To mill a card, a player puts the top card of their library into their graveyard.)

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

Release to Memory

Exile target opponent's graveyard. For each creature card exiled this way, create a 1/1 colorless Spirit creature token.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Eternal Dragon

Flying
{3}{W}{W}: Return this card from your graveyard to your hand. Activate only during your upkeep.
Plainscycling {2} ({2}, Discard this card: Search your library for a Plains card, reveal it, put it into your hand, then shuffle.)

Crush Contraband

Choose one or both —
• Exile target artifact.
• Exile target enchantment.

Aether Shockwave

Choose one —
• Tap all Spirits.
• Tap all non-Spirit creatures.

Sign in Blood

Target player draws two cards and loses 2 life.

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.

Remedy

Prevent the next 5 damage that would be dealt this turn to any number of targets, divided as you choose.

Deathbringer Liege

Other white creatures you control get +1/+1.
Other black creatures you control get +1/+1.
Whenever you cast a white spell, you may tap target creature.
Whenever you cast a black spell, you may destroy target creature if it's tapped.

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle this card, all creatures get -2/-2 until end of turn.

Altar's Reap

Your Temple Is Under Attack

Choose one —
• Pray for Protection — Creatures you control gain indestructible until end of turn.
• Strike a Deal — You and target opponent each draw two cards.

Obelisk of Urd

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +2/+2.