Whenever another permanent enters the battlefield under your control, each opponent mills a card.

Enchant creature card in a graveyard

When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.

Enchanted creature gets -1/-0.

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.

+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.

+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.

Target player draws X cards. Shuffle Blue Sun's Zenith into its owner's library.

Bojuka Bog enters the battlefield tapped.

When Bojuka Bog enters the battlefield, exile target player's graveyard.

{T}: Add {B}.

Living weapon (When this Equipment enters the battlefield, 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}

As Choked Estuary enters the battlefield, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters the battlefield tapped.

{T}: Add {U} or {B}.

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

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

Sacrifice Commander's Sphere: Draw a card.

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.

Counter target spell.

Return target nonland permanent you don't control to its owner's hand.

Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Darkslick Shores enters the battlefield tapped unless you control two or fewer other lands.

{T}: Add {U} or {B}.

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.

Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)

When you cycle Decree of Pain, all creatures get -2/-2 until end of turn.

Dimir Aqueduct enters the battlefield tapped.

When Dimir Aqueduct enters the battlefield, return a land you control to its owner's hand.

{T}: Add {U}{B}.

{1}{U}{B}: Exile target creature card from a graveyard. Dimir Doppelganger becomes a copy of that card, except it has this ability.

{1}, {T}: Add {U}{B}.

Destroy target nonblack creature.

Untap all nonland permanents you control.

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.

{T}: Add {U} or {B}.

{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.

{T}: Add {C}.

{U}{B}, {T}: Target player mills a card.

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

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

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.

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.

Destroy target nonartifact creature. Its controller mills cards equal to that creature's power.

Halimar Depths enters the battlefield tapped.

When Halimar Depths enters the battlefield, look at the top three cards of your library, then put them back in any order.

{T}: Add {U}.

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}

Target player mills X cards. If this spell was cast from a graveyard, that player mills twice that many cards instead.

Flashback {X}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

({T}: Add {U}.)

+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.

+2: Look at the top card of target player's library. You may put that card on the bottom of that player's library.

0: Draw three cards, then put two cards from your hand on top of your library in any order.

-1: Return target creature to its owner's hand.

-12: Exile all cards from target player's library, then that player shuffles their hand into their library.

{5}, {T}: Target player mills X cards, where X is the number of cards in that player's graveyard.

Inspired -- Whenever King Macar, the Gold-Cursed becomes untapped, you may exile target creature. If you do, create a Gold token. (It's an artifact with "Sacrifice this artifact: Add one mana of any color.")

Hexproof

Whenever a creature card is put into an opponent's graveyard from anywhere, you may have Lazav, Dimir Mastermind become a copy of that card, except its name is Lazav, Dimir Mastermind, it's legendary in addition to its other types, and it has hexproof and this ability.

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

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.

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.

{T}: Add {C}.

{1}, {T}, Sacrifice Mind Stone: Draw a card.

Whenever an opponent casts their first spell each turn, that player exiles the top card of their library. If it's a nonland card, you may cast it without paying its mana cost.

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

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.

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

{B}: Regenerate Mortivore.

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

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

{T}: Add {C}.

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

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.

Whenever you cast a spell, untap all nonland permanents you control.

At the beginning of your upkeep, target opponent mills three cards, then you draw a card for each land card put into their graveyard this way.

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."

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

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

Target player mills X cards and you gain X life.

Shuffle all cards from your graveyard into your library. Target player mills that many cards.

Counter target spell. Its controller mills two cards.

You have no maximum hand size.

{T}: Add {C}.

Kicker {7} (You may pay an additional {7} as you cast this spell.)

Search target player's library for up to three cards, exile them, then that player shuffles. If this spell was kicked, instead search that player's library for up to fifteen cards, exile them, then that player shuffles.

Devoid (This card has no color.)

Whenever a land enters the battlefield under an opponent's control, that player exiles the top two cards of their library and you draw two cards.

{T}: Add {C}{C}.

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.

Target opponent mills thirteen cards.

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

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.

({T}: Add {U} or {B}.)

Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

({T}: Add {B}.)

{T}: Add {C}.

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

{T}: Add {C}.

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

Temple of Deceit enters the battlefield tapped.

When Temple of Deceit enters the battlefield, scry 1.

{T}: Add {U} or {B}.

{T}: Add {C}{C}. Activate only if you control five or more lands.

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

Counter target spell. Its controller mills three cards.

You may activate abilities of creatures you control as though those creatures had haste.

{1}, {T}: Untap target creature.

Target player mills half their library, rounded down.

Defender

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

Choose a card name. Target player reveals cards from the top of their library until a card with that name is revealed. If it is, that player puts the rest of the revealed cards into their graveyard and puts the card with the chosen name on top of their library. Otherwise, the player shuffles.

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

Defender

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

Defender

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

({T}: Add {U} or {B}.)

As Watery Grave enters the battlefield, you may pay 2 life. If you don't, it enters the battlefield tapped.

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

Islandwalk, swampwalk (This creature can't be blocked as long as defending player controls an Island or a Swamp.)

Whenever Wrexial, the Risen Deep deals combat damage to a player, you may cast target instant or sorcery card from that player's graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.