Millstone

Doorkeeper

Defender
{2}{U}, {T}: Target player mills X cards, where X is the number of creatures you control with defender.

Riddlekeeper

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

Chronic Flooding

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

Didn't Say Please

Counter target spell. Its controller mills three cards.

Wall of Tears

Defender (This creature can't attack.)
Whenever Wall of Tears blocks a creature, return that creature to its owner's hand at end of combat.

Tower of Murmurs

{8}, {T}: Target player mills eight cards.

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Larder Zombie

Defender
Tap three untapped creatures you control: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Guard Gomazoa

Defender, flying
Prevent all combat damage that would be dealt to Guard Gomazoa.

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.)

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Cranial Archive

{2}, Exile Cranial Archive: Target player shuffles their graveyard into their library. Draw a card.

Aetherize

Return all attacking creatures to their owner's hand.

Fraying Sanity

Enchant player
At the beginning of each end step, enchanted player mills X cards, where X is the number of cards put into their graveyard from anywhere this turn.

Wall of Runes

Defender (This creature can't attack.)
When Wall of Runes enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Island

Curse of the Bloody Tome

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

Evanescent Intellect

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

Sage's Row Denizen

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

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control Time of Ice.
III — Return all tapped creatures to their owners' hands.