Have

Thriving Isle

This land enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Towering-Wave Mystic

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

Don't Have

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Island

Thought Scour

Target player mills two cards.
Draw a card.

Traumatize

Target player mills half their library, rounded down.

Vedalken Entrancer

Capture Sphere

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
When this Aura enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

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.)

Talent of the Telepath

Target opponent reveals the top seven cards of their library. You may cast an instant or sorcery spell from among them without paying its mana cost. Then that player puts the rest into their graveyard.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, you may cast up to two instant and/or sorcery spells from among the revealed cards instead of one.

Selhoff Occultist

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

Fleet Swallower

Whenever this creature attacks, target player mills half their library, rounded up.

Riddlekeeper

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

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.)

Weight of Memory

Draw three cards. Target player mills three cards.

Memory Erosion

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

Milling

Belltower Sphinx

Flying
Whenever a source deals damage to this creature, that source's controller mills that many cards.

Thought Collapse

Counter target spell. Its controller mills three cards.

Sweep Away

Return target creature to its owner's hand. If that creature is attacking, you may put it on top of its owner's library instead.

Reckless Scholar

{T}: Target player draws a card, then discards a card.