Venture Deeper

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

Merfolk Secretkeeper

Merfolk Secretkeeper // Venture Deeper

Tale's End

Counter target activated ability, triggered ability, or legendary spell.

Unexplained Disappearance

Return target creature to its owner's hand.
Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Island

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Tamiyo, Collector of Tales

Spells and abilities your opponents control can't cause you to discard cards or sacrifice permanents.
+1: Choose a nonland card name, then reveal the top four cards of your library. Put all cards with the chosen name from among them into your hand and the rest into your graveyard.
−3: Return target card from your graveyard to your hand.

Forest

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.

Negate

Drowned Secrets

Whenever you cast a blue spell, target player mills two cards.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

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.)

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Didn't Say Please

Counter target spell. Its controller mills three cards.

Jace, Wielder of Mysteries

If you would draw a card while your library has no cards in it, you win the game instead.
+1: Target player mills two cards. Draw a card.
−8: Draw seven cards. Then if your library has no cards in it, you win the game.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Unsummon

Return target creature to its owner's hand.

Castle Vantress

This land enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.