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.

Have

Quintorius, Loremaster

Vigilance
At the beginning of your end step, exile target noncreature, nonland card from your graveyard. Create a 3/2 red and white Spirit creature token.
{1}{R}{W}, {T}, Sacrifice a Spirit: Choose target card exiled with Quintorius. You may cast that card this turn without paying its mana cost. If that spell would be put into a graveyard, put it on the bottom of its owner's library instead.

Temple of the False God

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

Skycloud Expanse

Skybridge Towers

This land enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice this land: Draw a card.

Azorius Chancery

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Catlike Curiosity

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
If Catlike Curiosity would be put into a graveyard from anywhere, exile it instead.

Mischievous Catgeist

Whenever this creature deals combat damage to a player, draw a card.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mischievous Catgeist // Catlike Curiosity

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.

Venerable Warsinger

Vigilance, trample
Whenever this creature deals combat damage to a player, you may return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of damage this creature dealt to that player.

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

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.

Ethereal Investigator

Flying
When this creature enters, investigate X times, where X is the number of opponents you have. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you draw your second card each turn, create a 1/1 white 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.

Geistlight Snare

This spell costs {1} less to cast if you control a Spirit. It also costs {1} less to cast if you control an enchantment.
Counter target spell unless its controller pays {3}.

Cliffgate

This land enters tapped.
As this land enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Lorehold Command

Choose two —
• Create a 3/2 red and white Spirit creature token.
• Creatures you control get +1/+0 and gain indestructible and haste until end of turn.
• Lorehold Command deals 3 damage to any target. Target player gains 3 life.
• Sacrifice a permanent, then draw two cards.

Sift Through Sands

Draw two cards, then discard a card.
If you've cast a spell named Peer Through Depths and a spell named Reach Through Mists this turn, you may search your library for a card named The Unspeakable, put it onto the battlefield, then shuffle.

Blessed Breath

Target creature you control gains protection from the color of your choice until end of turn.
Splice onto Arcane {W} (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.)

Boros Garrison

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Lorehold Campus

This land enters tapped.
{T}: Add {R} or {W}.
{4}, {T}: Scry 1.

Supreme Phantom

Flying
Other Spirits you control get +1/+1.

Boros Signet

Mystic Monastery

This land enters tapped.
{T}: Add {U}, {R}, or {W}.

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.

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.

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Nebelgast Herald

Flash
Flying
Whenever this creature or another Spirit you control enters, tap target creature an opponent controls.

Grand Arbiter Augustin IV

White spells you cast cost {1} less to cast.
Blue spells you cast cost {1} less to cast.
Spells your opponents cast cost {1} more to cast.

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Command Tower

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

Myojin of Blooming Dawn

Myojin of Blooming Dawn enters with an indestructible counter on it if you cast it from your hand.
Remove an indestructible counter from Myojin of Blooming Dawn: Create a 1/1 colorless Spirit creature token for each permanent you control.

Reach Through Mists

Reconstruct History

Return up to one target artifact card, up to one target enchantment card, up to one target instant card, up to one target sorcery card, and up to one target planeswalker card from your graveyard to your hand.
Exile Reconstruct History.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Pearl Medallion

White spells you cast cost {1} less to cast.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Ghost of Ramirez DePietro

Ghost of Ramirez DePietro can't be blocked by creatures with toughness 3 or greater.
Whenever Ghost of Ramirez DePietro deals combat damage to a player, choose up to one target card in a graveyard that was discarded or put there from a library this turn. Put that card into its owner's hand.
Partner (You can have two commanders if both have partner.)

Lanterns' Lift

Enchant creature
Enchanted creature gets +1/+1 and has flying.
If Lanterns' Lift would be put into a graveyard from anywhere, exile it instead.

Lantern Bearer

Flying
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Lantern Bearer // Lanterns' Lift

Izzet Signet

Consuming Vortex

Return target creature to its owner's hand.
Splice onto Arcane {3}{U} (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.)

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Island

Sire of the Storm

Flying
Whenever you cast a Spirit or Arcane spell, you may draw a card.

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Fire Diamond

This artifact enters tapped.
{T}: Add {R}.

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Radiant Destiny

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
As this enchantment enters, choose a creature type.
Creatures you control of the chosen type get +1/+1. As long as you have the city's blessing, they also have vigilance.

Angel of Flight Alabaster

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

Clifftop Retreat

This land enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

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.

Sevinne's Reclamation

Return target permanent card with mana value 3 or less from your graveyard to the battlefield. If this spell was cast from a graveyard, you may copy this spell and may choose a new target for the copy.
Flashback {4}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Thriving Heath

This land enters tapped. As it enters, choose a color other than white.
{T}: Add {W} or one mana of the chosen color.

Spectral Shepherd

Flying
{1}{U}: Return target Spirit you control to its owner's hand.

Raugrin Crystal

{T}: Add {U}, {R}, or {W}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Donal, Herald of Wings

Whenever you cast a nonlegendary creature spell with flying, you may copy it, except the copy is a 1/1 Spirit in addition to its other types. Do this only once each turn. (The copy becomes a token.)

Distant Melody

Choose a creature type. Draw a card for each permanent you control of that type.

Drogskol Captain

Flying
Other Spirit creatures you control get +1/+1 and have hexproof. (They can't be the targets of spells or abilities your opponents control.)

Jeskai Banner

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

Oyobi, Who Split the Heavens

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

Thriving Isle

This land enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Spectral Arcanist

Flying
When this creature enters, you may cast an instant or sorcery spell with mana value less than or equal to the number of Spirits you control from a graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

Plains

Kykar, Wind's Fury

Flying
Whenever you cast a noncreature spell, create a 1/1 white Spirit creature token with flying.
Sacrifice a Spirit: Add {R}.

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Jeskai Ascendancy

Whenever you cast a noncreature spell, creatures you control get +1/+1 until end of turn. Untap those creatures.
Whenever you cast a noncreature spell, you may draw a card. If you do, discard a card.

Peer Through Depths

Look at the top five cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in any order.

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Frostboil Snarl

As this land enters, you may reveal an Island or Mountain card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {R}.

Arcane Signet

Rattlechains

Flash
Flying
When this creature enters, target Spirit gains hexproof until end of turn.
You may cast Spirit spells as though they had flash.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Promise of Bunrei

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

Long-Forgotten Gohei

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

Windborn Muse

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

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Inspiring Leader

Commander creatures you own have "Creature tokens you control get +2/+2."

Ravenform

Exile target artifact or creature. Its controller creates a 1/1 blue Bird creature token with flying.
Foretell {U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Narset of the Ancient Way

+1: You gain 2 life. Add {U}, {R}, or {W}. Spend this mana only to cast a noncreature spell.
−2: Draw a card, then you may discard a card. When you discard a nonland card this way, Narset deals damage equal to that card's mana value to target creature or planeswalker.
−6: You get an emblem with "Whenever you cast a noncreature spell, this emblem deals 2 damage to any target."

Empyrean Eagle

Flying
Other creatures you control with flying get +1/+1.

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.

Jeskai Charm

Choose one —
• Put target creature on top of its owner's library.
• Jeskai Charm deals 4 damage to target opponent or planeswalker.
• Creatures you control get +1/+1 and gain lifelink until end of turn.

Spirit Bonds

Whenever a nontoken creature you control enters, you may pay {W}. If you do, create a 1/1 white Spirit creature token with flying.
{1}{W}, Sacrifice a Spirit: Target non-Spirit creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Millicent, Restless Revenant

Affinity for Spirits (This spell costs {1} less to cast for each Spirit you control.)
Flying
Whenever Millicent or another nontoken Spirit you control dies or deals combat damage to a player, create a 1/1 white Spirit creature token with flying.

Shacklegeist

Flying
This creature can block only creatures with flying.
Tap two untapped Spirits you control: Tap target creature you don't control.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.