Darkwater Catacombs

Wharf Infiltrator

Skulk (This creature can't be blocked by creatures with greater power.)
Whenever Wharf Infiltrator deals combat damage to a player, you may draw a card. If you do, discard a card.
Whenever you discard a creature card, you may pay {2}. If you do, create a 3/2 colorless Eldrazi Horror creature token.

Tasha's Hideous Laughter

Each opponent exiles cards from the top of their library until that player has exiled cards with total mana value 20 or more.

Chasm Skulker

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker.
When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

Glimpse the Unthinkable

Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Sunken Hollow

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Sol Ring

Maddening Cacophony

Kicker {3}{U}
Each opponent mills eight cards. If this spell was kicked, instead each opponent mills half their library, rounded up.

Watery Grave

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

Grell Philosopher

Aberrant Tinkering — When Grell Philosopher enters and at the beginning of your upkeep, each Horror you control gains all activated abilities of target artifact an opponent controls until end of turn. You may spend blue mana as though it were mana of any color to activate those abilities.

Traumatize

Target player mills half their library, rounded down.

Island

Sire of Stagnation

Devoid (This card has no color.)
Whenever a land an opponent controls enters, that player exiles the top two cards of their library and you draw two cards.

Nephalia Drownyard

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

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.

Mind Grind

Each opponent reveals cards from the top of their library until they reveal X land cards, then puts all cards revealed this way into their graveyard. X can't be 0.

Ashiok, Nightmare Muse

+1: Create a 2/3 blue and black Nightmare creature token with "Whenever this creature attacks or blocks, each opponent exiles the top two cards of their library."
−3: Return target nonland permanent to its owner's hand, then that player exiles a card from their hand.
−7: You may cast up to three spells from among face-up cards your opponents own from exile without paying their mana costs.

Command Tower

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

Cut Your Losses

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Target player mills half their library, rounded down.

Elder Brain

Menace
Whenever Elder Brain attacks a player, exile all cards from that player's hand, then they draw that many cards. You may play lands and cast spells from among the exiled cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

Drowned Catacomb

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

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Murkwater Pathway

Clearwater Pathway

Clearwater Pathway // Murkwater Pathway

Nemesis of Reason

Whenever Nemesis of Reason attacks, defending player mills ten cards.

Sludge Monster

Whenever Sludge Monster enters or attacks, put a slime counter on up to one other target creature.
Non-Horror creatures with slime counters on them lose all abilities and have base power and toughness 2/2.

Brainstealer Dragon

Flying
At the beginning of your end step, exile the top card of each opponent's library. You may play those cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.
Whenever a nonland permanent an opponent owns enters the battlefield under your control, they lose life equal to its mana value.

Mind Funeral

Target opponent reveals cards from the top of their library until four land cards are revealed. That player puts all cards revealed this way into their graveyard.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Drown in Dreams

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Target player draws X cards.
• Target player mills twice X cards.

Ashiok, Nightmare Weaver

+2: Exile the top three cards of target opponent's library.
−X: Put a creature card with mana value X exiled with Ashiok, Nightmare Weaver onto the battlefield under your control. That creature is a Nightmare in addition to its other types.
−10: Exile all cards from all opponents' hands and graveyards.

Grazilaxx, Illithid Scholar

Whenever a creature you control becomes blocked, you may return it to its owner's hand.
Whenever one or more creatures you control deal combat damage to a player, draw a card.

Persistent Nightmare

Skulk (This creature can't be blocked by creatures with greater power.)
When Persistent Nightmare deals combat damage to a player, return it to its owner's hand.

Startled Awake

Target opponent mills thirteen cards.
{3}{U}{U}: Put Startled Awake from your graveyard onto the battlefield transformed. Activate only as a sorcery.

Startled Awake // Persistent Nightmare

Tormod's Crypt

{T}, Sacrifice Tormod's Crypt: Exile target player's graveyard.

Temple of Deceit

Temple of Deceit enters tapped.
When Temple of Deceit enters, scry 1.
{T}: Add {U} or {B}.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Rogue's Passage

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

Lightning Greaves

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

Fraying Sanity

Enchant player
At the beginning of each end step, enchanted player mills X cards, where X is the number of cards put into their graveyard from anywhere this turn.

Dimir Signet

Counterspell

Zellix, Sanity Flayer

Hive Mind — Whenever a player mills one or more creature cards, you create a 1/1 black Horror creature token.
{1}, {T}: Target player mills three cards.
Choose a Background (You can have a Background as a second commander.)

Leyline of the Void

If Leyline of the Void is in your opening hand, you may begin the game with it on the battlefield.
If a card would be put into an opponent's graveyard from anywhere, exile it instead.

Endless Evil

Enchant creature you control
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except the token is 1/1.
When enchanted creature dies, if that creature was a Horror, return Endless Evil to its owner's hand.

Sphinx's Tutelage

Whenever you draw a card, target opponent mills two cards. If two nonland cards that share a color were milled this way, repeat this process.
{5}{U}: Draw a card, then discard a card.

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Memory Erosion

Whenever an opponent casts a spell, that player mills two cards.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Arcane Signet

Tainted Isle

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

Choked Estuary

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

Crypt Incursion

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

Scavenger Grounds

{T}: Add {C}.
{2}, {T}, Sacrifice a Desert: Exile all graveyards.

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Psychic Strike

Counter target spell. Its controller mills two cards.

Phenax, God of Deception

Indestructible
As long as your devotion to blue and black is less than seven, Phenax isn't a creature.
Creatures you control have "{T}: Target player mills X cards, where X is this creature's toughness."

Thought Collapse

Counter target spell. Its controller mills three cards.

Didn't Say Please

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Relic of Progenitus

{T}: Target player exiles a card from their graveyard.
{1}, Exile Relic of Progenitus: Exile all graveyards. Draw a card.

Swamp

Ravenous Chupacabra

When Ravenous Chupacabra enters, destroy target creature an opponent controls.

Mind Flayer

Dominate Monster — When Mind Flayer enters, gain control of target creature for as long as you control Mind Flayer.

Mesmeric Orb

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

Umbris, Fear Manifest

Umbris, Fear Manifest gets +1/+1 for each card your opponents own in exile.
Whenever Umbris or another Nightmare or Horror you control enters, target opponent exiles cards from the top of their library until they exile a land card.

Awoken Horror

When this creature transforms into Awoken Horror, return all non-Horror creatures to their owners' hands.

Thing in the Ice

Defender
Thing in the Ice enters with four ice counters on it.
Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.

Thing in the Ice // Awoken Horror

Court of Cunning

When Court of Cunning 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.)

Drown in the Loch

Choose one —
• Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard.
• Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Shipwreck Marsh

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

Psionic Ritual

Replicate—Tap an untapped Horror you control. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Exile target instant or sorcery card from a graveyard and copy it. You may cast the copy without paying its mana cost.
Exile Psionic Ritual.

Uchuulon

Uchuulon's power is equal to the number of Crabs, Oozes, and/or Horrors you control.
Horrific Symbiosis — At the beginning of your end step, exile up to one target creature card from an opponent's graveyard. If you do, create a token that's a copy of Uchuulon.

Toxrill, the Corrosive

At the beginning of each end step, put a slime counter on each creature you don't control.
Creatures you don't control get -1/-1 for each slime counter on them.
Whenever a creature you don't control with a slime counter on it dies, create a 1/1 black Slug creature token.
{U}{B}, Sacrifice a Slug: Draw a card.

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Ruin Crab

Landfall — Whenever a land you control enters, each opponent mills three cards. (To mill a card, a player puts the top card of their library into their graveyard.)

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Windfall

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

Fractured Sanity

Each opponent mills fourteen cards.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)
When you cycle Fractured Sanity, each opponent mills four cards.

Dark Ritual

Captain N'ghathrod

Horrors you control have menace.
Whenever a Horror you control deals combat damage to a player, that player mills that many cards.
At the beginning of your end step, choose target artifact or creature card in an opponent's graveyard that was put there from their library this turn. Put it onto the battlefield under your control.

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)