River of Tears

{T}: Add {U}. If you played a land this turn, add {B} instead.

Arcane Signet

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

Thassa's Oracle

When this creature enters, look at the top X cards of your library, where X is your devotion to blue. Put up to one of them on top of your library and the rest on the bottom of your library in a random order. If X is greater than or equal to the number of cards in your library, you win the game. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Court of Cunning

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, any number of target players each mill two cards. If you're the monarch, each of those players mills ten cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Thran Dynamo

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Swamp

Archaeomender

When this creature enters, return target artifact card from your graveyard to your hand.

Unfulfilled Desires

{1}, Pay 1 life: Draw a card, then discard a card.

Doomwake Giant

Constellation — Whenever this creature or another enchantment you control enters, creatures your opponents control get -1/-1 until end of turn.

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Omen Hawker

{T}: Add {C}{U}. Spend this mana only to activate abilities.

Hydroelectric Laboratory

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)

Matzalantli, the Great Door // The Core

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Crow of Dark Tidings

Flying
When this creature enters or dies, mill two cards. (Put the top two cards of your library into your graveyard.)

Island

Thalakos Deceiver

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever this creature attacks and isn't blocked, you may sacrifice it. If you do, gain control of target creature. (This effect lasts indefinitely.)

Millikin

{T}, Mill a card: Add {C}. (To mill a card, put the top card of your library into your graveyard.)

Emry, Lurker of the Loch

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
When Emry enters, mill four cards.
{T}: Choose target artifact card in your graveyard. You may cast that card this turn. (You still pay its costs. Timing rules still apply.)

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Fell Mire

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Fell the Profane

Fell the Profane // Fell Mire

Loyal Subordinate

Menace (This creature can't be blocked except by two or more creatures.)
Lieutenant — At the beginning of combat on your turn, if you control your commander, each opponent loses 3 life.

Otherworldly Gaze

Surveil 3. (Look at the top three cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Living Death

Each player exiles all creature cards from their graveyard, then sacrifices all creatures they control, then puts all cards they exiled this way onto the battlefield.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Teferi's Veil

Whenever a creature you control attacks, it phases out at end of combat. (While it's phased out, it's treated as though it doesn't exist. It phases in before you untap during your next untap step.)

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.)

Fallaji Archaeologist

When this creature enters, mill three cards. You may put a noncreature, nonland card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on this creature. (To mill a card, put the top card of your library into your graveyard.)

Singularity Rupture

Destroy all creatures, then any number of target players each mill half their library, rounded down.

Archon of Cruelty

Flying
Whenever this creature enters or attacks, target opponent sacrifices a creature or planeswalker of their choice, discards a card, and loses 3 life. You draw a card and gain 3 life.

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Wake the Dead

Cast this spell only during combat on an opponent's turn.
Return X target creature cards from your graveyard to the battlefield. Sacrifice those creatures at the beginning of the next end step.

Archfiend of Despair

Flying
Your opponents can't gain life.
At the beginning of each end step, each opponent loses life equal to the life that player lost this turn. (Damage causes loss of life.)

Ashiok, Dream Render

Spells and abilities your opponents control can't cause their controller to search their library.
−1: Target player mills four cards. Then exile each opponent's graveyard.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Out of the Tombs

At the beginning of your upkeep, put two eon counters on this enchantment, then mill cards equal to the number of eon counters on it.
If you would draw a card while your library has no cards in it, instead return a creature card from your graveyard to the battlefield. If you can't, you lose the game.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard this card: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Darkwater Catacombs

Gloomlake Verge

{T}: Add {U}.
{T}: Add {B}. Activate only if you control an Island or a Swamp.

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. This land deals 1 damage to you.

Jace, the Perfected Mind

Compleated ({U/P} can be paid with {U} or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)
+1: Until your next turn, up to one target creature gets -3/-0.
−2: Target player mills three cards. Then if a graveyard has twenty or more cards in it, you draw three cards. Otherwise, you draw a card.
−X: Target player mills three times X cards.

Minamo, School at Water's Edge

{T}: Add {U}.
{U}, {T}: Untap target legendary permanent.

Talisman of Dominance

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

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)

Noxious Gearhulk

Menace
When this creature enters, you may destroy another target creature. If a creature is destroyed this way, you gain life equal to its toughness.

Necron Deathmark

Flash
Synaptic Disintegrator — When this creature enters, destroy up to one target creature and target player mills three cards.

Patriar's Seal

{T}: Add one mana of any color.
{1}, {T}: Untap target legendary creature you control.

Military Intelligence

Whenever you attack with two or more creatures, draw a card.

Command Tower

Fetid Pools

({T}: Add {U} or {B}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Sunken Hollow

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

Convergence of Dominion

Dynastic Command Node — As long as you control your commander, activated abilities of cards in your graveyard cost {2} less to activate. This effect can't reduce the mana in that ability's activation cost to less than one mana.
Translocation Protocols — {3}, {T}: Mill three cards.

Deep Analysis

Target player draws two cards.
Flashback—{1}{U}, Pay 3 life. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Shipwreck Marsh

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Sunken Ruins

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

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Terror Tide

Fathomless descent — All creatures get -X/-X until end of turn, where X is the number of permanent cards in your graveyard.

Wurmcoil Engine

Deathtouch, lifelink
When this creature dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Sol Ring

Dimir Signet

Sundial of the Infinite

{1}, {T}: End the turn. Activate only during your turn. (Exile all spells and abilities from the stack. Discard down to your maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)

Vantress Visions

Copy target activated or triggered ability you control. You may choose new targets for the copy.

Virtue of Knowledge

If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Virtue of Knowledge // Vantress Visions

Fellwar Stone

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

Rootwater Diver

{T}, Sacrifice this creature: Return target artifact card from your graveyard to your hand.

Snapcaster Mage

Flash
When this creature enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Rottenmouth Viper

As an additional cost to cast this spell, you may sacrifice any number of nonland permanents. This spell costs {1} less to cast for each permanent sacrificed this way.
Whenever this creature enters or attacks, put a blight counter on it. Then for each blight counter on it, each opponent loses 4 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Tribute Mage

When this creature enters, you may search your library for an artifact card with mana value 2, reveal that card, put it into your hand, then shuffle.

Reef Worm

When this creature dies, create a 3/3 blue Fish creature token with "When this token dies, create a 6/6 blue Whale creature token with 'When this token dies, create a 9/9 blue Kraken creature token.'"

Choked Estuary

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

Undercity Sewers

({T}: Add {U} or {B}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Soporific Springs

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Frantic Search

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

Perpetual Timepiece

{T}: Mill two cards.
{2}, Exile this artifact: Shuffle any number of target cards from your graveyard into your library.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Ripples of Undeath

At the beginning of your first main phase, mill three cards. Then you may pay {1} and 3 life. If you do, put a card from among those cards into your hand.

Kokusho, the Evening Star

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

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Worn Powerstone

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

Glimpse the Unthinkable

Dusk Mangler

As an additional cost to cast this spell, sacrifice a creature, discard a card, or pay 4 life.
When this creature enters, each opponent sacrifices a creature of their choice, discards a card, and loses 4 life.

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Watery Grave

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

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Floating-Dream Zubera

When this creature dies, draw a card for each Zubera that died this turn.

Nephalia Drownyard

{T}: Add {C}.
{1}{U}{B}, {T}: Target player mills three cards.

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Return target artifact card from your graveyard to your hand.

Damnation

Destroy all creatures. They can't be regenerated.

Exotic Orchard

Myr Retriever

When this creature dies, return another target artifact card from your graveyard to your hand.