Swamp

Dispersal

Each opponent returns a nonland permanent they control with the highest mana value among permanents they control to its owner's hand, then discards a card.

Discovery

Surveil 2, then draw a card. (To surveil 2, look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Discovery // Dispersal

Tyrant's Scorn

Choose one —
• Destroy target creature with mana value 3 or less.
• Return target creature to its owner's hand.

Deadly Visit

Destroy target creature.
Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Dimir Guildgate

Dimir Guildgate enters tapped.
{T}: Add {U} or {B}.

Darkblade Agent

As long as you've surveilled this turn, Darkblade Agent has deathtouch and "Whenever this creature deals combat damage to a player, you draw a card."

Dimir Spybug

Flying
Menace (This creature can't be blocked except by two or more creatures.)
Whenever you surveil, put a +1/+1 counter on Dimir Spybug.

Island

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.)

House Guildmage

{1}{U}, {T}: Target creature doesn't untap during its controller's next untap step.
{2}{B}, {T}: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Enhanced Surveillance

You may look at an additional two cards each time you surveil.
Exile Enhanced Surveillance: Shuffle your graveyard into your library.

Whisper Agent

Flash
When Whisper Agent enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Submerged Boneyard

Submerged Boneyard enters tapped.
{T}: Add {U} or {B}.

Thoughtbound Phantasm

Defender
Whenever you surveil, put a +1/+1 counter on Thoughtbound Phantasm.
As long as Thoughtbound Phantasm has three or more +1/+1 counters on it, it can attack as though it didn't have defender.

Disinformation Campaign

When Disinformation Campaign enters, you draw a card and each opponent discards a card.
Whenever you surveil, return Disinformation Campaign to its owner's hand.