Thoughtbound Phantasm

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

Nightveil Sprite

Flying
Whenever this creature attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Thief of Sanity

Flying
Whenever this creature deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Concoct

Surveil 3, then return a creature card from your graveyard to the battlefield.

Connive

Gain control of target creature with power 2 or less.

Connive // Concoct

Thought Erasure

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Blood Operative

Lifelink
When this creature enters, you may exile target card from a graveyard.
Whenever you surveil, if this card is in your graveyard, you may pay 3 life. If you do, return this card to your hand.

Disinformation Campaign

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

Pilfering Imp

Flying
{1}{B}, {T}, Sacrifice this creature: Target opponent reveals their hand. You choose a nonland card from it. That player discards that card. Activate only as a sorcery.

Whispering Snitch

Whenever you surveil for the first time each turn, this creature deals 1 damage to each opponent and you gain 1 life.

Ritual of Soot

Destroy all creatures with mana value 3 or less.

Drowned Secrets

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

Island

Nightveil Predator

Flying, deathtouch
Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Watery Grave

({T}: Add {U} or {B}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Vicious Rumors

Vicious Rumors deals 1 damage to each opponent. Each opponent discards a card, then mills a card. You gain 1 life.

Etrata, the Silencer

Etrata can't be blocked.
Whenever Etrata deals combat damage to a player, exile target creature that player controls and put a hit counter on that card. That player loses the game if they own three or more exiled cards with hit counters on them. Etrata's owner shuffles Etrata into their library.

Dream Eater

Flash
Flying
When this creature enters, surveil 4. When you do, you may return target nonland permanent an opponent controls to its owner's hand. (To surveil 4, look at the top four cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Plaguecrafter

When this creature enters, each player sacrifices a creature or planeswalker of their choice. Each player who can't discards a card.

Unmoored Ego

Choose a card name. Search target opponent's graveyard, hand, and library for up to four cards with that name and exile them. That player shuffles, then draws a card for each card exiled from their hand this way.

Enhanced Surveillance

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

Lazav, the Multifarious

When Lazav enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{X}: Lazav becomes a copy of target creature card in your graveyard with mana value X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.

Narcomoeba

Flying
When this card is put into your graveyard from your library, you may put it onto the battlefield.

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.)

Dimir Guildgate

This land enters tapped.
{T}: Add {U} or {B}.

Mnemonic Betrayal

Exile all opponents' graveyards. You may cast spells from among those cards this turn, and mana of any type can be spent to cast them. At the beginning of the next end step, if any of those cards remain exiled, return them to their owners' graveyards.
Exile Mnemonic Betrayal.

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 this creature.

Doom Whisperer

Flying, trample
Pay 2 life: 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.)

Sinister Sabotage

Counter target spell.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Artful Takedown

Choose one or both —
• Tap target creature.
• Target creature gets -2/-4 until end of turn.

Devious Cover-Up

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard. You may shuffle up to four target cards from your graveyard into your library.

Darkblade Agent

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

Dispersal

Each opponent returns a nonland permanent they control with the greatest 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

Notion Rain

Surveil 2, then draw two cards. Notion Rain deals 2 damage to you. (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.)

Mission Briefing

Surveil 2, then choose an instant or sorcery card in your graveyard. You may cast it this turn. If that spell would be put into your graveyard, exile it instead. (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.)