Gilded Lotus

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.)

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.

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

Windborn Muse

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

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.

Moonlit Strider

Sacrifice this creature: Target creature you control gains protection from the color of your choice until end of turn.
Soulshift 3 (When this creature dies, you may return target Spirit card with mana value 3 or less from your graveyard to your hand.)

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Drumbellower

Flying
Untap all creatures you control during each other player's untap step.

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.

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.

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Wedding Ring

When this artifact enters, if it was cast, target opponent creates a token that's a copy of it.
Whenever an opponent who controls an artifact named Wedding Ring draws a card during their turn, you draw a card.
Whenever an opponent who controls an artifact named Wedding Ring gains life during their turn, you gain that much life.

Gravitational Shift

Creatures with flying get +2/+0.
Creatures without flying get -2/-0.

Supreme Phantom

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

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.

Favorable Winds

Creatures you control with flying get +1/+1.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Counterspell

Haunting Imitation

Each player reveals the top card of their library. For each creature card revealed this way, create a token that's a copy of that card, except it's 1/1, it's a Spirit in addition to its other types, and it has flying. If no creature cards were revealed this way, return Haunting Imitation to its owner's hand.

Nebelgast Herald

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

Fellwar Stone

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

Exotic Orchard

Skycloud Expanse

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice this artifact: Create a 10/10 colorless Eldrazi creature token.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Thran Dynamo

Lazotep Plating

Amass Zombies 1. (Put a +1/+1 counter on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)
You and permanents you control gain hexproof until end of turn. (You and they can't be the targets of spells or abilities your opponents control.)

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.)

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

On Wings of Gold

Creatures you control that are Zombies and/or tokens get +1/+1 and have flying.
Whenever one or more cards leave your graveyard, create a 1/1 white Zombie creature token.

Selfless Spirit

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

Empyrean Eagle

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

Skullclamp

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

Dreamshackle Geist

Flying
At the beginning of combat on your turn, choose up to one —
• Tap target creature.
• Target creature doesn't untap during its controller's next untap step.

Azorius Chancery

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

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice this artifact: Draw two cards.

Eidolon of Obstruction

First strike
Loyalty abilities of planeswalkers your opponents control cost {1} more to activate.

Plains

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.")

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

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Reflections of Littjara

As this enchantment enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a 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.)

Propaganda

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

Render Silent

Counter target spell. Its controller can't cast spells this turn.

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Remorseful Cleric

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

Sire of the Storm

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

Ghostly Pilferer

Whenever this creature becomes untapped, you may pay {2}. If you do, draw a card.
Whenever an opponent casts a spell from anywhere other than their hand, draw a card.
Discard a card: This creature can't be blocked this turn.

Breath of the Sleepless

You may cast Spirit spells as though they had flash.
Whenever you cast a creature spell during an opponent's turn, tap up to one target creature.

Arcane Signet

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

Island

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Harsh Mercy

Each player chooses a creature type. Destroy all creatures that aren't of a type chosen this way. They can't be regenerated.

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.

Shacklegeist

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

Temple of Civilization

(Transforms from Ojer Taq, Deepest Foundation.)
{T}: Add {W}.
{2}{W}, {T}: Transform this land. Activate only if you attacked with three or more creatures this turn and only as a sorcery.

Ojer Taq, Deepest Foundation

Vigilance
If one or more creature tokens would be created under your control, three times that many of those tokens are created instead.
When Ojer Taq dies, return it to the battlefield tapped and transformed under its owner's control.

Ojer Taq, Deepest Foundation // Temple of Civilization

Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Ghastly Mimicry

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except it's a Spirit in addition to its other types.
If Ghastly Mimicry would be put into a graveyard from anywhere, exile it instead.

Mirrorhall Mimic

You may have this creature enter as a copy of any creature on the battlefield, except it's a Spirit in addition to its other types.
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mirrorhall Mimic // Ghastly Mimicry

Mind Stone

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

Wayfarer's Bauble

{2}, {T}, Sacrifice this artifact: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Port Town

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

Talisman of Progress

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

Ghostly Prison

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.

Command Tower

Teferi's Ageless Insight

If you would draw a card except the first one you draw in each of your draw steps, draw two cards instead.

Occult Epiphany

Draw X cards, then discard X cards. Create a 1/1 white Spirit creature token with flying for each card type among cards discarded this way.

Moorland Haunt

{T}: Add {C}.
{W}{U}, {T}, Exile a creature card from your graveyard: Create a 1/1 white Spirit creature token with flying.

Reliquary Tower

Unclaimed Territory

As this land enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Azorius 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.

Sol Ring

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

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.