Hedron Crab

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

Counterspell

Duress

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

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.)

Visions of Beyond

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

Glimpse the Unthinkable

Fractured Sanity

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

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Swamp

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.)