Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Thoughtweft Gambit

Tap all creatures your opponents control and untap all creatures you control.

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Aether Shockwave

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

Gadwick, the Wizened

When Gadwick, the Wizened enters, draw X cards.
Whenever you cast a blue spell, tap target nonland permanent an opponent controls.

Niblis of Frost

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Whenever you cast an instant or sorcery spell, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Timin, Youthful Geist

Partner with Rhoda, Geist Avenger (When this creature enters, target player may put Rhoda into their hand from their library, then shuffle.)
Flying
At the beginning of each combat, tap up to one target creature.

Opposition

Tap an untapped creature you control: Tap target artifact, creature, or land.

Ballynock Trapper

{T}: Tap target creature.
Whenever you cast a white spell, you may untap Ballynock Trapper.

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

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.)

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Plains

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.

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Azorius Guildmage

{2}{W}: Tap target creature.
{2}{U}: Counter target activated ability. (Mana abilities can't be targeted.)

Tidal Force

At the beginning of each upkeep, you may tap or untap target permanent.

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Court Street Denizen

Whenever another white creature you control enters, tap target creature an opponent controls.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Gideon's Avenger

Whenever a creature an opponent controls becomes tapped, put a +1/+1 counter on Gideon's Avenger.

Icy Blast

Tap X target creatures.
Ferocious — If you control a creature with power 4 or greater, those creatures don't untap during their controllers' next untap steps.

Tempest Caller

When Tempest Caller enters, tap all creatures target opponent controls.

Bond of Discipline

Tap all creatures your opponents control. Creatures you control gain lifelink until end of turn.

Downpour

Chilling Chronicle

{1}, {T}: Tap target nonland permanent. Transform Chilling Chronicle.

Mysterious Tome

{2}, {T}: Draw a card. Transform Mysterious Tome.

Mysterious Tome // Chilling Chronicle

Icy Manipulator

{1}, {T}: Tap target artifact, creature, or land.

Sunblast Angel

Flying
When Sunblast Angel enters, destroy all tapped creatures.

Azorius Chancery

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

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Citadel Siege

As Citadel Siege enters, choose Khans or Dragons.
• Khans — At the beginning of combat on your turn, put two +1/+1 counters on target creature you control.
• Dragons — At the beginning of combat on each opponent's turn, tap target creature that player controls.

Dismiss into Dream

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

Subjugator Angel

Flying
When Subjugator Angel enters, tap all creatures your opponents control.

Mistveil Plains

({T}: Add {W}.)
Mistveil Plains enters tapped.
{W}, {T}: Put target card from your graveyard on the bottom of your library. Activate only if you control two or more white permanents.

Minister of Impediments

({W/U} can be paid with either {W} or {U}.)
{T}: Tap target creature.

Glimpse the Sun God

Tap X target creatures. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Command Tower

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

Piercing Rays

Exile target tapped creature.
Forecast — {2}{W}, Reveal Piercing Rays from your hand: Tap target untapped creature. (Activate this ability only during your upkeep and only once each turn.)

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.)

Niblis of the Urn

Flying
Whenever Niblis of the Urn attacks, you may tap target creature.

Shacklegeist

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

Repel the Darkness

Tap up to two target creatures.
Draw a card.

Rhoda, Geist Avenger

Partner with Timin, Youthful Geist (When this creature enters, target player may put Timin into their hand from their library, then shuffle.)
Vigilance
Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, put a +1/+1 counter on Rhoda, Geist Avenger.

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 Mirrorhall Mimic 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

Prairie Stream

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

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Dungeon Geists

Flying
When Dungeon Geists enters, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Dungeon Geists.

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Feeling of Dread

Tap up to two target creatures.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Expel

Hot Soup

Equipped creature can't be blocked.
Whenever equipped creature is dealt damage, destroy it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

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.

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Gridlock

Chop Down

Destroy target creature with power 4 or greater. (Then exile this card. You may cast the creature later from exile.)

Giant Killer

Giant Killer // Chop Down

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.

Sentinel of the Eternal Watch

Vigilance (Attacking doesn't cause this creature to tap.)
At the beginning of combat on each opponent's turn, tap target creature that player controls.

Topplegeist

Flying
When Topplegeist enters, tap target creature an opponent controls.
Delirium — At the beginning of each opponent's upkeep, if there are four or more card types among cards in your graveyard, tap target creature that player controls.

Retreat to Coralhelm

Landfall — Whenever a land you control enters, choose one —
• You may tap or untap target creature.
• Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Port Town

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

Island

Swift Response

Gideon's Lawkeeper

Scepter of Dominance

Glacial Fortress

Glacial Fortress enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Tolarian Kraken

Whenever you draw a card, you may pay {1}. When you do, you may tap or untap target creature.

Arcane Lighthouse

{T}: Add {C}.
{1}, {T}: Until end of turn, creatures your opponents control lose hexproof and shroud and can't have hexproof or shroud.

Sun Titan

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

Turnabout

Choose artifact, creature, or land. Tap all untapped permanents of the chosen type target player controls, or untap all tapped permanents of that type that player controls.

Ensnare

You may return two Islands you control to their owner's hand rather than pay this spell's mana cost.
Tap all creatures.

Return to Dust

Exile target artifact or enchantment. If you cast this spell during your main phase, you may exile up to one other target artifact or enchantment.

Detection Tower

{T}: Add {C}.
{1}, {T}: Until end of turn, your opponents and creatures your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof.

Goldmeadow Harrier

Fatestitcher

{T}: You may tap or untap another target permanent.
Unearth {U} ({U}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Niblis of the Breath

Flying
{U}, {T}: You may tap or untap target creature.

Arcane Signet

Blustersquall

Tap target creature you don't control.
Overload {3}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Spectral Shepherd

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

Glacial Floodplain

({T}: Add {W} or {U}.)
Glacial Floodplain enters tapped.

Nimbus Maze

{T}: Add {C}.
{T}: Add {W}. Activate only if you control an Island.
{T}: Add {U}. Activate only if you control a Plains.

Sol Ring

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.