Vedalken Entrancer

Wood Sage

{T}: Choose a creature card name. Reveal the top four cards of your library and put all of them with that name into your hand. Put the rest into your graveyard.

Persistent Petitioners

{1}, {T}: Target player mills a card. (They put the top card of their library into their graveyard.)
Tap four untapped Advisors you control: Target player mills twelve cards.
A deck can have any number of cards named Persistent Petitioners.

Cathartic Adept

Selhoff Occultist

Whenever this creature or another creature dies, target player mills a card.

Broken Ambitions

Counter target spell unless its controller pays {X}. Clash with an opponent. If you win, that spell's controller mills four cards. (Each clashing player reveals the top card of their library, then puts that card on their choice of the top or bottom. A player wins if their card had a greater mana value.)

Countermand

Counter target spell. Its controller mills four cards.

Sage's Row Denizen

Whenever another blue creature you control enters, target player mills two cards.

Dampen Thought

Target player mills four cards.
Splice onto Arcane {1}{U} (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Towering-Wave Mystic

Whenever this creature deals damage, target player mills that many cards.

Merrow Witsniper

When this creature enters, target player mills a card.

Ghoulcaller's Bell

Enigma Eidolon

{U}, Sacrifice this creature: Target player mills three cards.
Whenever you cast a multicolored spell, you may return this card from your graveyard to your hand.

Screeching Sliver

All Slivers have "{T}: Target player mills a card."

Glistener Seer

This creature enters with three oil counters on it.
{T}, Remove an oil counter from this creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Homarid Explorer

When this creature enters, target player mills four cards.

Rotcrown Ghoul

When this creature dies, target player mills five cards.

Pelargir Survivor

{T}: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell.
{5}{U}, {T}: Target player mills three cards. (They put the top three cards of their library into their graveyard.)

Merfolk Mesmerist

Thought Collapse

Counter target spell. Its controller mills three cards.

Reef Pirates

Whenever this creature deals damage to an opponent, that player mills a card.

Chronic Flooding

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

Evanescent Intellect

Enchant creature
Enchanted creature has "{1}{U}, {T}: Target player mills three cards."

Glacial Grasp

Tap target creature. Its controller mills two cards. That creature doesn't untap during its controller's next untap step. (They put the top two cards of their library into their graveyard.)
Draw a card.

Grapple with the Past

Mill three cards, then you may return a creature or land card from your graveyard to your hand. (To mill three cards, put the top three cards of your library into your graveyard.)

Didn't Say Please

Dreadwaters

Target player mills X cards, where X is the number of lands you control.

Redtooth Genealogist

When this creature enters, create a Royal Role token attached to another target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1 and has ward {1}.)

Curse of the Bloody Tome

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