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."

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.

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.

Crypt Incursion

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

Geth, Lord of the Vault

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
{X}{B}: Put target artifact or creature card with mana value X from an opponent's graveyard onto the battlefield under your control tapped. Then that player mills X cards.

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.

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.

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.)

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.)

Dimir Signet

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.

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Pilfered Plans

Target player mills two cards. Draw two cards.

Anowon, the Ruin Thief

Other Rogues you control get +1/+1.
Whenever one or more Rogues you control deal combat damage to a player, that player mills a card for each 1 damage dealt to them. If the player mills at least one creature card this way, you draw a card. (To mill a card, a player puts the top card of their library into their graveyard.)

Mutilate

All creatures get -1/-1 until end of turn for each Swamp you control.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Kess, Dissident Mage

Flying
Once during each of your turns, you may cast an instant or sorcery spell from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead.

Merciless Executioner

When Merciless Executioner enters, each player sacrifices a creature.

Psychic Spiral

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

Arcane Signet

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

Blood Money

Destroy all creatures. For each nontoken creature destroyed this way, you create a tapped Treasure token.

Traumatize

Target player mills half their library, rounded down.

Mindcrank

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

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.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Curse of Opulence

Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this artifact: Add one mana of any color.")

Increasing Vengeance

Copy target instant or sorcery spell you control. If this spell was cast from a graveyard, copy that spell twice instead. You may choose new targets for the copies.
Flashback {3}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fellwar Stone

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

Exotic Orchard

Crux of Fate

Choose one —
• Destroy all Dragon creatures.
• Destroy all non-Dragon creatures.

Island

Mountain

Lord Xander, the Collector

When Lord Xander, the Collector enters, target opponent discards half the cards in their hand, rounded down.
Whenever Lord Xander attacks, defending player mills half their library, rounded down.
When Lord Xander dies, target opponent sacrifices half the nonland permanents they control, rounded down.

Necromantic Selection

Destroy all creatures, then return a creature card put into a graveyard this way to the battlefield under your control. It's a black Zombie in addition to its other colors and types. Exile Necromantic Selection.

Evolving Wilds

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

Swamp

Notion Rain

Surveil 2, then draw two cards. Notion Rain deals 2 damage to you. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

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.

Izzet Charm

Choose one —
• Counter target noncreature spell unless its controller pays {2}.
• Izzet Charm deals 2 damage to target creature.
• Draw two cards, then discard two cards.

Galvanic Iteration

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.
Flashback {1}{U}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Fleshbag Marauder

When Fleshbag Marauder enters, each player sacrifices a creature.

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Plaguecrafter

When Plaguecrafter enters, each player sacrifices a creature or planeswalker. Each player who can't discards a card.

Prismari Command

Choose two —
• Prismari Command deals 2 damage to any target.
• Target player draws two cards, then discards two cards.
• Target player creates a Treasure token.
• Destroy target artifact.

Sol Ring

Frantic Search

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

Maddening Cacophony

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

Demon's Disciple

When Demon's Disciple enters, each player sacrifices a creature or planeswalker.

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.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Black Sun's Zenith

Put X -1/-1 counters on each creature. Shuffle Black Sun's Zenith into its owner's library.

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.

Decree of Pain

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.

Nemesis of Reason

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

Command Tower

Grixis Panorama

{T}: Add {C}.
{1}, {T}, Sacrifice Grixis Panorama: Search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Izzet Signet

Stitcher Geralf

{2}{U}, {T}: Each player mills three cards. Exile up to two creature cards put into graveyards this way. Create an X/X blue Zombie creature token, where X is the total power of the cards exiled this way.

Bojuka Bog

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

Wall of Lost Thoughts

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

Life's Finale

Destroy all creatures, then search target opponent's library for up to three creature cards and put them into their graveyard. Then that player shuffles.

Mesmeric Orb

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

You Find the Villains' Lair

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rakdos Signet

Terramorphic Expanse

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

Thought Scour

Target player mills two cards.
Draw a card.

Cathartic Reunion

As an additional cost to cast this spell, discard two cards.
Draw three cards.

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.