Chronic Flooding

Enchant land
Whenever enchanted land becomes tapped, its controller mills three cards.

Dream Twist

Target player mills three cards.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Patient Rebuilding

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.

Tome Scour

Pilfered Plans

Target player mills two cards. Draw two cards.

Curse of the Bloody Tome

Enchant player
At the beginning of enchanted player's upkeep, that player mills two cards.

Mirko Vosk, Mind Drinker

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.

Swamp

Didn't Say Please

Counter target spell. Its controller mills three cards.

Counterspell

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Psychic Corrosion

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

Memory Erosion

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

Island

Thoughtcutter Agent

{U}{B}, {T}: Target player loses 1 life and reveals their hand.

Paranoid Delusions

Target player mills three cards.
Cipher (Then you may exile this spell card encoded on a creature you control. Whenever that creature deals combat damage to a player, its controller may cast a copy of the encoded card without paying its mana cost.)