Thundering Mightmare

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Thundering Mightmare is paired with another creature, each of those creatures has "Whenever an opponent casts a spell, put a +1/+1 counter on this creature."

Island

Mountain

Scion of Draco

Domain — This spell costs {2} less to cast for each basic land type among lands you control.
Flying
Each creature you control has vigilance if it's white, hexproof if it's blue, lifelink if it's black, first strike if it's red, and trample if it's green.

Distant Melody

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

Radiant Fountain

When Radiant Fountain enters, you gain 2 life.
{T}: Add {C}.

Rakdos Guildgate

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

Swift Response

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

Counterspell

Kokusho, the Evening Star

Flying
When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Tanglebloom

Bloodfell Caves

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

Clarion Spirit

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

Glorious Sunrise

At the beginning of combat on your turn, choose one —
• Creatures you control get +1/+1 and gain trample until end of turn.
• Target land gains "{T}: Add {G}{G}{G}" until end of turn.
• Draw a card if you control a creature with power 3 or greater.
• You gain 3 life.

Supreme Phantom

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

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.

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.

Sungold Barrage

Destroy target creature with toughness 4 or greater.

Vorpal Sword

Equipped creature gets +2/+0 and has deathtouch.
{5}{B}{B}{B}: Until end of turn, Vorpal Sword gains "Whenever equipped creature deals combat damage to a player, that player loses the game."
Equip {B}{B}

Sol Ring

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.

O-Kagachi Made Manifest

O-Kagachi Made Manifest is all colors.
Flying, trample
Whenever O-Kagachi Made Manifest attacks, defending player chooses a nonland card in your graveyard. Return that card to your hand. O-Kagachi Made Manifest gets +X/+0 until end of turn, where X is the mana value of that card.

The Kami War

(As this Saga enters and after your draw step, add a lore counter.)
I — Exile target nonland permanent an opponent controls.
II — Return up to one other target nonland permanent to its owner's hand. Then each opponent discards a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Kami War // O-Kagachi Made Manifest

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Rattlechains

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

O-Kagachi, Vengeful Kami

Flying, trample
Whenever O-Kagachi, Vengeful Kami deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

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.)

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.

Zagoth Crystal

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

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.

Nebelgast Herald

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever Nebelgast Herald or another Spirit you control enters, tap target creature an opponent controls.

Swords to Plowshares

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

Iname, Life Aspect

When Iname, Life Aspect dies, you may exile it. If you do, return any number of target Spirit cards from your graveyard to your hand.

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Timeless Lotus

Timeless Lotus enters tapped.
{T}: Add {W}{U}{B}{R}{G}.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Spectral Shepherd

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

Ketria Crystal

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

Savai Crystal

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

Ghost-Lit Drifter

Flying
{2}{U}: Another target creature gains flying until end of turn.
Channel — {X}{U}, Discard Ghost-Lit Drifter: X target creatures gain flying until end of turn.

Unnatural Growth

At the beginning of each combat, double the power and toughness of each creature you control until end of turn.

Darkmoss Bridge

Darkmoss Bridge enters tapped.
Indestructible
{T}: Add {B} or {G}.

Brokers Hideout

When Brokers Hideout enters, sacrifice it. When you do, search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Swamp

Cabaretti Courtyard

When Cabaretti Courtyard enters, sacrifice it. When you do, search your library for a basic Mountain, Forest, or Plains card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Raugrin Crystal

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

Wind-Scarred Crag

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

Crypt Incursion

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Eternal Taskmaster

Eternal Taskmaster enters tapped.
Whenever Eternal Taskmaster attacks, you may pay {2}{B}. If you do, return target creature card from your graveyard to your hand.

Ryusei, the Falling Star

Flying
When Ryusei, the Falling Star dies, it deals 5 damage to each creature without flying.

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.

Stormrider Spirit

Scoured Barrens

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

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Millicent, Restless Revenant

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

Hypothesizzle

Draw two cards. Then you may discard a nonland card. When you do, Hypothesizzle deals 4 damage to target creature.

Armory of Iroas

Whenever equipped creature attacks, put a +1/+1 counter on it.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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.

Boros Guildgate

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

Hofri Ghostforge

Spirits you control get +1/+1 and have trample and haste.
Whenever another nontoken creature you control dies, exile it. If you do, create a token that's a copy of that creature, except it's a Spirit in addition to its other types and it has "When this creature leaves the battlefield, return the exiled card to its owner's graveyard."

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.)

Indatha Crystal

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

Kodama's Reach

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.)

Pristine Talisman

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

Plummet

Mana Flare

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Voiceless Spirit

Kazandu Nectarpot

Landfall — Whenever a land you control enters, you gain 1 life.

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, Dawnhart Martyr'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

Plains

Dismal Backwater

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

Jodah's Codex

Domain — {5}, {T}: Draw a card. This ability costs {1} less to activate for each basic land type among lands you control.

Hanged Executioner

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

Lich-Knights' Conquest

Sacrifice any number of artifacts, enchantments, and/or tokens. Return that many creature cards from your graveyard to the battlefield.

Kyodai, Soul of Kamigawa

Flash
Flying
When Kyodai, Soul of Kamigawa enters, another target permanent gains indestructible for as long as you control Kyodai.
{W}{U}{B}{R}{G}: Kyodai gets +5/+5 until end of turn.

Forest

Jugan, the Rising Star

Flying
When Jugan, the Rising Star dies, you may distribute five +1/+1 counters among any number of target creatures.