Traumatize

Target player mills half their library, rounded down.

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.

Thought Vessel

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

Cyclonic Rift

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.")

Terisian Mindbreaker

Whenever this creature 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.)

An Offer You Can't Refuse

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

Undead Alchemist

If a Zombie you control would deal combat damage to a player, instead that player mills that many cards.
Whenever a creature card is put into an opponent's graveyard from their library, exile that card and create a 2/2 black Zombie creature token.

Lightning Greaves

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

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Memory Erosion

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

Hedron Crab

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

Nanogene Conversion

Choose target creature you control. Each other creature becomes a copy of that creature until end of turn, except it isn't legendary.

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.

Soulless Jailer

Permanent cards in graveyards can't enter the battlefield.
Players can't cast noncreature spells from graveyards or exile.

Counterspell

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.

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Maddening Cacophony

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

Aetherize

Return all attacking creatures to their owner's hand.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Mjölnir, Storm Hammer

When Mjölnir enters, attach it to target legendary creature you control.
Whenever equipped creature attacks, tap target creature defending player controls and put a stun counter on it. Then Mjölnir deals damage to each opponent equal to the number of tapped creatures that opponent controls.
Equip {4}

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.)

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Windfall

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

Mindcrank

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

Get Out

Choose one —
• Counter target creature or enchantment spell.
• Return one or two target creatures and/or enchantments you own to your hand.

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Sky Diamond

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

Irenicus's Vile Duplication

Create a token that's a copy of target creature you control, except the token has flying and it isn't legendary.

Mirelurk Queen

Vigilance
When this creature enters, target player gets two rad counters.
Whenever one or more nonland cards are milled, draw a card, then put a +1/+1 counter on this creature. This ability triggers only once each turn.

Mesmeric Orb

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

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Jace, the Perfected Mind

Compleated ({U/P} can be paid with {U} or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.)
+1: Until your next turn, up to one target creature gets -3/-0.
−2: Target player mills three cards. Then if a graveyard has twenty or more cards in it, you draw three cards. Otherwise, you draw a card.
−X: Target player mills three times X cards.

Riddlekeeper

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

Island

Auton Soldier

You may have this creature enter as a copy of any creature on the battlefield, except it isn't legendary, is an artifact in addition to its other types, and has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

Fleet Swallower

Whenever this creature attacks, target player mills half their library, rounded up.

War Room

{T}: Add {C}.
{3}, {T}, Pay life equal to the number of colors in your commanders' color identity: Draw a card.

Unable to Scream

Enchant creature
Enchanted creature loses all abilities and is a Toy artifact creature with base power and toughness 0/2 in addition to its other types.
As long as enchanted creature is face down, it can't be turned face up.

Midnight Clock

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

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.)

Scavenger Grounds

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

Abhorrent Oculus

As an additional cost to cast this spell, exile six cards from your graveyard.
Flying
At the beginning of each opponent's upkeep, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Fear of Sleep Paralysis

Flying
Eerie — Whenever this creature or another enchantment you control enters and whenever you fully unlock a Room, tap up to one target creature and put a stun counter on it.
Stun counters can't be removed from permanents your opponents control. (They won't untap if they have stun counters.)

Psychic Corrosion

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

Grafdigger's Cage

Creature cards in graveyards and libraries can't enter the battlefield.
Players can't cast spells from graveyards or libraries.

Sakashima of a Thousand Faces

You may have Sakashima enter as a copy of another creature you control, except it has Sakashima's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Lavaspur Boots

Equipped creature gets +1/+0 and has haste and ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {1}

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Arcane Signet

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

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Negate

The Mindskinner

The Mindskinner can't be blocked.
If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.

Jace's Phantasm

Flying
This creature gets +4/+4 as long as an opponent has ten or more cards in their graveyard.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Vantress Gargoyle

Flying
This creature can't attack unless defending player has seven or more cards in their graveyard.
This creature can't block unless you have four or more cards in hand.
{T}: Each player mills a card.

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Sol Ring

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

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.)

Spark Double

You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

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}

Propaganda

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

Reliquary Tower

Court of Cunning

When this enchantment 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.)

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.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Visions of Beyond

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

Giggling Skitterspike

Indestructible
Whenever this creature attacks, blocks, or becomes the target of a spell, it deals damage equal to its power to each opponent.
{5}: Monstrosity 5. (If this creature isn't monstrous, put five +1/+1 counters on it and it becomes monstrous.)