Whispering Snitch

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

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.)

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

Cast Down

Swamp

Gravewaker

Flying (This creature can't be blocked except by creatures with flying or reach.)
{5}{B}{B}: Return target creature card from your graveyard to the battlefield tapped.

Riddlemaster Sphinx

Flying (This creature can't be blocked except by creatures with flying or reach.)
When Riddlemaster Sphinx enters, you may return target creature an opponent controls to its owner's hand.

Dimir Locket

{T}: Add {U} or {B}.
{U/B}{U/B}{U/B}{U/B}, {T}, Sacrifice Dimir Locket: Draw two cards.

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.

Thief of Sanity

Flying
Whenever Thief of Sanity 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.

Nightveil Sprite

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

Dimir Guildgate

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

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

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.)

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.)

Syncopate

Counter target spell unless its controller pays {X}. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Quasiduplicate

Create a token that's a copy of target creature you control.
Jump-start (You may cast this card from your graveyard by discarding a card in addition to paying its other costs. Then exile this card.)

Whisper Agent

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

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."