Venture Deeper

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Merfolk Secretkeeper

Destroy target nonartifact creature. Its controller mills cards equal to that creature's power.

Exile all creature cards from target player's graveyard. You gain 3 life for each card exiled this way.

Target creature and all other creatures with the same name as that creature get -2/-2 until end of turn.

Wight of Precinct Six gets +1/+1 for each creature card in your opponents' graveyards.

Flying
Whenever Shriekgeist deals combat damage to a player, that player mills two cards.

Counter target artifact or enchantment spell.

Counter target spell. Its controller mills three cards.

Lifelink
When Desperate Bloodseeker enters, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Counter target spell. Its controller mills two cards.

Target player mills three cards.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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

Target player mills two cards.
Draw a card.

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

Flying
Jace's Phantasm gets +4/+4 as long as an opponent has ten or more cards in their graveyard.