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.)

Persist

Return target nonlegendary creature card from your graveyard to the battlefield with a -1/-1 counter on it.

Palantír of Orthanc

At the beginning of your end step, put an influence counter on Palantír of Orthanc and scry 2. Then target opponent may have you draw a card. If that player doesn't, you mill X cards, where X is the number of influence counters on Palantír of Orthanc, and that player loses life equal to the total mana value of those cards.

Deranged Assistant

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

Shipwreck Marsh

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

Fascination

Choose one —
• Each player draws X cards.
• Each player mills X cards.

Stitcher's Supplier

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

Command Tower

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

Shadow Kin

Flash
At the beginning of your upkeep, each player mills three cards. You may exile a creature card from among the cards milled this way. If you do, this creature becomes a copy of that card, except it has this ability.

Extract from Darkness

Each player mills two cards. Then you put a creature card from a graveyard onto the battlefield under your control.

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.

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.

Dreadhound

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
Whenever a creature dies or a creature card is put into a graveyard from a library, each opponent loses 1 life.

Altar of the Brood

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

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}

Evolving Wilds

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

Terramorphic Expanse

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Talisman of Dominance

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

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.)

Archaeomancer

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

Sky Diamond

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

Doomed Necromancer

{B}, {T}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield.

Undead Butler

When this creature enters, mill three cards. (Put the top three cards of your library into your graveyard.)
When this creature dies, you may exile it. When you do, return target creature card from your graveyard to your hand.

Morphic Pool

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

Worry Beads

At the beginning of each player's upkeep, that player mills a card.

Swamp

Riddlekeeper

Whenever a creature attacks you or a planeswalker you control, that creature's controller mills two cards.

Drowned Catacomb

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

Lord of the Forsaken

Flying, trample
{B}, Sacrifice another creature: Target player mills three cards.
Pay 1 life: Add {C}. Spend this mana only to cast a spell from your graveyard.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Island

Terror of Towashi

Deathtouch
Whenever this creature attacks, you may pay {3}{B}. When you do, return target creature card from your graveyard to the battlefield. It's a Phyrexian in addition to its other types.

Fractured Sanity

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

Folio of Fancies

Players have no maximum hand size.
{X}{X}, {T}: Each player draws X cards.
{2}{U}, {T}: Each opponent mills cards equal to the number of cards in their hand.

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.)

Sol Ring

Haunted One

Commander creatures you own have "Whenever this creature becomes tapped, it and other creatures you control that share a creature type with it each get +2/+0 and gain undying until end of turn." (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Stormtide Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
All lands are Islands in addition to their other types.
Creatures without flying or islandwalk can't attack.

Havengul Lich

{1}: You may cast target creature card in a graveyard this turn. When you cast it this turn, this creature gains all activated abilities of that card until end of turn.

Forbidden Alchemy

Look at the top four cards of your library. Put one of them into your hand and the rest into your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Unseal the Necropolis

Each player mills three cards. Then you return up to two creature cards from your graveyard to your hand. (To mill three cards, a player puts the top three cards of their library into their graveyard.)

Charcoal Diamond

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

Perpetual Timepiece

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

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.)

Animate Dead

Enchant creature card in a graveyard
When this Aura enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with this Aura." Return enchanted creature card to the battlefield under your control and attach this Aura to it. When this Aura leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Armored Skaab

When this creature enters, mill four cards.

Watery Grave

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

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

Altar of Dementia

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

Vohar, Vodalian Desecrator

{T}: Draw a card, then discard a card. If you discarded an instant or sorcery card this way, each opponent loses 1 life and you gain 1 life.
{2}, Sacrifice Vohar: You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead. Activate only as a sorcery.

Dimir Signet

Dreamborn Muse

At the beginning of each player's upkeep, that player mills X cards, where X is the number of cards in their hand.

Millikin

Gyruda, Doom of Depths

Companion — Your starting deck contains only cards with even mana values. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
When Gyruda enters, each player mills four cards. Put a creature card with an even mana value from among the milled cards onto the battlefield under your control.

Dig Up the Body

Casualty 1 (As you cast this spell, you may sacrifice a creature with power 1 or greater. When you do, copy this spell.)
Mill two cards, then you may return a creature card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

Arcane Signet

Underground Sea

Phyrexian Delver

When this creature enters, return target creature card from your graveyard to the battlefield. You lose life equal to that card's mana value.

Necrotic Ooze

As long as this creature is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Ghoulcaller's Bell

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.

Apprentice Necromancer

{B}, {T}, Sacrifice this creature: Return target creature card from your graveyard to the battlefield. That creature gains haste. At the beginning of the next end step, sacrifice it.

Aven Heartstabber

Flying
As long as there are five or more mana values among cards in your graveyard, this creature gets +2/+2 and has deathtouch.
When this creature dies, mill two cards, then draw a card.

Incarnation Technique

Demonstrate (When you cast this spell, you may copy it. If you do, choose an opponent to also copy it.)
Mill five cards, then return a creature card from your graveyard to the battlefield.

Stitch Together

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

Duskmantle, House of Shadow

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

Sunken Hollow

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

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.

Mesmeric Orb

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

Mindcrank

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

Eye Collector

Flying
Whenever this creature deals combat damage to a player, each player mills a card. (Each player puts the top card of their library into their graveyard.)

Sands of Delirium

Psychic Spiral

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

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.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.