Memory Erosion

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

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.

The Ancient One

Descend 8 — The Ancient One can't attack or block unless there are eight or more permanent cards in your graveyard.
{2}{U}{B}: Draw a card, then discard a card. When you discard a card this way, target player mills cards equal to its mana value.

Restless Reef

Restless Reef enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Restless Reef becomes a 4/4 blue and black Shark creature with deathtouch. It's still a land.
Whenever Restless Reef attacks, target player mills four cards.

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.

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.

Dimir Signet

Thought Collapse

Counter target spell. Its controller mills three cards.

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

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.

Thran Dynamo

Mortivore

Mortivore's power and toughness are each equal to the number of creature cards in all graveyards.
{B}: Regenerate Mortivore. (The next time this creature would be destroyed, instead tap it, remove it from combat, and heal all damage on it.)

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.)

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.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Corrupted Shapeshifter

Devoid (This card has no color.)
As Corrupted Shapeshifter enters, it becomes your choice of a 3/3 creature with flying, a 2/5 creature with vigilance, or a 0/12 creature with defender.

Propaganda

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

Island

Mirko Vosk, Mind Drinker

Flying
Whenever Mirko Vosk, Mind Drinker deals combat damage to a player, that player reveals cards from the top of their library until they reveal four land cards, then puts those cards into their graveyard.

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards.

Sunken Hollow

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

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on Midnight Clock.
At the beginning of each upkeep, put an hour counter on Midnight Clock.
When the twelfth hour counter is put on Midnight Clock, shuffle your hand and graveyard into your library, then draw seven cards. Exile Midnight Clock.

Nihil Spellbomb

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard.
When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Dreamscape Artist

{2}{U}, {T}, Discard a card, Sacrifice a land: Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

Jace, Memory Adept

+1: Draw a card. Target player mills a card.
0: Target player mills ten cards.
−7: Any number of target players each draw twenty cards.

Didn't Say Please

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.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Bojuka Bog

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

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Hover Barrier

Charix, the Raging Isle

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Eater of the Dead

{0}: If Eater of the Dead is tapped, exile target creature card from a graveyard and untap Eater of the Dead.

Barrowgoyf

Deathtouch, lifelink
Barrowgoyf's power is equal to the number of card types among cards in all graveyards and its toughness is equal to that number plus 1.
Whenever Barrowgoyf deals combat damage to a player, you may mill that many cards. If you do, you may put a creature card from among them into your hand.

Thought Scour

Target player mills two cards.
Draw a card.

Deepmuck Desperado

Whenever you commit a crime, each opponent mills three cards. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Mindcrank

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

Nighthowler

Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Nighthowler and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

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."

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

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.

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.)

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Swamp

Nephalia Drownyard

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

Traumatize

Target player mills half their library, rounded down.

Wight of Precinct Six

Wight of Precinct Six gets +1/+1 for each creature card in your opponents' graveyards.

Command Tower

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

Can't Wake Up

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Cruel Somnophage

Cruel Somnophage's power and toughness are each equal to the number of creature cards in all graveyards.

Cruel Somnophage // Can't Wake Up

Duskmantle Guildmage

{1}{U}{B}: Whenever a card is put into an opponent's graveyard from anywhere this turn, that player loses 1 life.
{2}{U}{B}: Target player mills two cards.

Visions of Beyond

Draw a card. If a graveyard has twenty or more cards in it, draw three cards instead.

Sol Ring

Psychic Corrosion

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

Glimpse the Unthinkable

Crackdown Construct

Whenever you activate an ability of an artifact or creature that isn't a mana ability, Crackdown Construct gets +1/+1 until end of turn.

Bonehoard

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards.
Equip {2}

Arcane Signet

Dramatic Reversal

Untap all nonland permanents you control.

Hydroelectric Laboratory

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

Hydroelectric Specimen

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

Hydroelectric Specimen // Hydroelectric Laboratory

Maddening Cacophony

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

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.

Crypt Incursion

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

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Altar of the Pantheon

Your devotion to each color and each combination of colors is increased by one.
{T}: Add one mana of any color. If you control a God, a Demigod, or a legendary enchantment, you gain 1 life.

Psychic Strike

Counter target spell. Its controller mills two cards.

Glacial Wall

Wall of Lost Thoughts

Defender
When Wall of Lost Thoughts enters, target player mills four cards.

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

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.)

Mesmeric Orb

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

Drowned Catacomb

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

Talisman of Dominance

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

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Terisian Mindbreaker

Whenever Terisian Mindbreaker attacks, defending player mills half their library, rounded up.
Unearth {1}{U}{U}{U} ({1}{U}{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.)

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.)

An Offer You Can't Refuse

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