Counterspell

Thought Scour

Target player mills two cards.
Draw a card.

Swamp

Lurking Informant

({U/B} can be paid with either {U} or {B}.)
{2}, {T}: Look at the top card of target player's library. You may put that card into that player's graveyard.

Merfolk Observer

When Merfolk Observer enters, look at the top card of target player's library.

Island

Ghoulcaller's Bell

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Divest

Target player reveals their hand. You choose an artifact or creature card from it. That player discards that card.

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Portent

Look at the top three cards of target player's library, then put them back in any order. You may have that player shuffle.
Draw a card at the beginning of the next turn's upkeep.

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Thoughtpicker Witch

{1}, Sacrifice a creature: Look at the top two cards of target opponent's library, then exile one of them.

Cathartic Adept

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.