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.

Drowned Secrets

Whenever you cast a blue spell, target player mills two cards.

Altar of Dementia

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

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.

Harmonic Prodigy

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
If a triggered ability of a Shaman or another Wizard you control triggers, that ability triggers an additional time.

Book Burning

Any player may have Book Burning deal 6 damage to them. If no one does, target player mills six cards.

Dual Strike

When you next cast an instant or sorcery spell with mana value 4 or less this turn, copy that spell. You may choose new targets for the copy.
Foretell {R} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

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.)

Silverbluff Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {R}.

Stream of Thought

Target player mills four cards. You shuffle up to four cards from your graveyard into your library.
Replicate {2}{U}{U} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)

Didn't Say Please

Counter target spell. Its controller mills three cards.

Dual Casting

Enchant creature
Enchanted creature has "{R}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy."

Veyran, Voice of Duality

Magecraft — Whenever you cast or copy an instant or sorcery spell, Veyran gets +1/+1 until end of turn.
If you casting or copying an instant or sorcery spell causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.

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.)

Mountain

Beacon Bolt

Beacon Bolt deals damage to target creature equal to the total number of instant and sorcery cards you own in exile and in your graveyard.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Mind Sculpt

Thought Collapse

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 greater.

Overwhelmed Apprentice

When this creature enters, each opponent mills two cards. Then you scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

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.

Island

Echo Mage

Level up {1}{U} ({1}{U}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 2-3
2/4
{U}{U}, {T}: Copy target instant or sorcery spell. You may choose new targets for the copy.
LEVEL 4+
2/5
{U}{U}, {T}: Copy target instant or sorcery spell twice. You may choose new targets for the copies.

Bloodwater Entity

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When this creature enters, you may put target instant or sorcery card from your graveyard on top of your library.

Meletis Charlatan

{2}{U}, {T}: The controller of target instant or sorcery spell copies it. That player may choose new targets for the copy.

Glasspool Shore

Glasspool Mimic

You may have this creature enter as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Mimic // Glasspool Shore

Teferi's Tutelage

When this enchantment enters, draw a card, then discard a card.
Whenever you draw a card, target opponent mills two cards. (They put the top two cards of their library into their graveyard.)

Maddening Cacophony

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

Wall of Lost Thoughts

Defender (This creature can't attack.)
When this creature enters, target player mills four cards. (They put the top four cards of their library into their graveyard.)

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Compelling Argument

Target player mills five cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Reliquary Tower

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

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

Riddlekeeper

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

Painter's Servant

As this creature enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Errant, Street Artist

Flash
Defender, haste
{1}{U}, {T}: Copy target spell you control that wasn't cast. You may choose new targets for the copy.

Doublecast

When you next cast an instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Mindcrank

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

Propaganda

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

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.)

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.

Jace's Erasure

Whenever you draw a card, you may have target player mill a card.

Geistblast

Geistblast deals 2 damage to any target.
{2}{U}, Exile this card from your graveyard: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

Memory Erosion

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

League Guildmage

{3}{U}, {T}: Draw a card.
{X}{R}, {T}: Copy target instant or sorcery spell you control with mana value X. You may choose new targets for the copy.

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)

Rootha, Mercurial Artist

{2}, Return Rootha to its owner's hand: Copy target instant or sorcery spell you control. You may choose new targets for the copy.