Millstone

Drown in the Loch

Choose one —
• Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard.
• Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Siren of the Silent Song

Flying
Inspired — Whenever Siren of the Silent Song becomes untapped, each opponent discards a card, then each opponent mills a card.

Island

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.

Psychic Drain

Target player mills X cards and you gain X life.

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Curse of the Bloody Tome

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

Swamp

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Compelling Argument

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

Psychic Strike

Counter target spell. Its controller mills two cards.

Chronic Flooding

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

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.

Chill of Foreboding

Each player mills five cards.
Flashback {7}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Coral Colony

Defender
{1}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender. (To mill a card, a player puts the top card of their library into their graveyard.)

Didn't Say Please

Counter target spell. Its controller mills three cards.

Fog Bank

Defender, flying
Prevent all combat damage that would be dealt to and dealt by Fog Bank.