Shadow Alley Denizen

Whenever another black creature enters the battlefield under your control, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Sewer Nemesis

As Sewer Nemesis enters the battlefield, choose a player.
Sewer Nemesis's power and toughness are each equal to the number of cards in the chosen player's graveyard.
Whenever the chosen player casts a spell, that player mills a card.

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

Netherborn Altar

{T}, Put a soul counter on Netherborn Altar: Put your commander into your hand from the command zone. Then you lose 3 life for each soul counter on Netherborn Altar.

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Dauthi Trapper

{T}: Target creature gains shadow until end of turn. (It can block or be blocked by only creatures with shadow.)

Thieves' Guild Enforcer

Flash
Whenever Thieves' Guild Enforcer or another Rogue enters the battlefield under your control, each opponent mills two cards.
As long as an opponent has eight or more cards in their graveyard, Thieves' Guild Enforcer gets +2/+1 and has deathtouch.

Bone Shredder

Flying
Echo {2}{B} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
When Bone Shredder enters the battlefield, destroy target nonartifact, nonblack creature.

Manifold Key

{1}, {T}: Untap another target artifact.
{3}, {T}: Target creature can't be blocked this turn.

Shriekhorn

Shriekhorn enters the battlefield with three charge counters on it.
{T}, Remove a charge counter from Shriekhorn: Target player mills two cards.

Shriekmaw

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
When Shriekmaw enters the battlefield, destroy target nonartifact, nonblack creature.
Evoke {1}{B} (You may cast this spell for its evoke cost. If you do, it's sacrificed when it enters the battlefield.)

Confession Dial

When Confession Dial enters the battlefield, surveil 3.
{T}: Target legendary creature card in your graveyard gains escape until end of turn. The escape cost is equal to its mana cost plus exile three other cards from your graveyard. (You may cast it from your graveyard for its escape cost this turn.)

Sonic Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Untap another target artifact.
{2}, {T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{3}, {T}: Target creature can't be blocked this turn.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Shared Trauma

Join forces — Starting with you, each player may pay any amount of mana. Each player mills X cards, where X is the total amount of mana paid this way.

Street Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Cycling—Pay 2 life. (Pay 2 life, Discard this card: Draw a card.)

Predator, Flagship

{2}: Target creature gains flying until end of turn.
{5}, {T}: Destroy target creature with flying.

Ravenous Chupacabra

When Ravenous Chupacabra enters the battlefield, destroy target creature an opponent controls.

Codex Shredder

{T}: Target player mills a card. (They put the top card of their library into their graveyard.)
{5}, {T}, Sacrifice Codex Shredder: Return target card from your graveyard to your hand.

Vicious Rumors

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

Thieves' Tools

When Thieves' Tools enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equipped creature can't be blocked as long as its power is 3 or less.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Mishra's Bauble

{T}, Sacrifice Mishra's Bauble: Look at the top card of target player's library. Draw a card at the beginning of the next turn's upkeep.

Silver Shroud Costume

Flash
When Silver Shroud Costume enters the battlefield, attach it to target creature you control. That creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
Equipped creature can't be blocked.
Equip {3}

Wedding Invitation

When Wedding Invitation enters the battlefield, draw a card.
{T}, Sacrifice Wedding Invitation: Target creature can't be blocked this turn. If it's a Vampire, it also gains lifelink until end of turn.

Eye Collector

Flying
Whenever Eye Collector deals combat damage to a player, each player mills a card.

Soratami Cloud Chariot

{2}: Target creature you control gains flying until end of turn.
{2}: Prevent all combat damage that would be dealt to and dealt by target creature you control this turn.

Hot Soup

Equipped creature can't be blocked.
Whenever equipped creature is dealt damage, destroy it.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Ghoulcaller's Bell

Gnawing Vermin

When Gnawing Vermin enters the battlefield, target player mills two cards.
When Gnawing Vermin dies, target creature you don't control gets -1/-1 until end of turn.

Tinybones, the Pickpocket

Deathtouch
Whenever Tinybones, the Pickpocket deals combat damage to a player, you may cast target nonland permanent card from that player's graveyard, and mana of any type can be spent to cast that spell.

Necron Deathmark

Flash
Synaptic Disintegrator — When Necron Deathmark enters the battlefield, destroy up to one target creature and target player mills three cards.

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.