Go for the Throat

Smoke Bomb

Flash
All creatures have shroud. (They can't be the targets of spells or abilities.)
At the beginning of your upkeep, sacrifice this artifact. When you do, target creature you control can't be blocked this turn.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Evie Frye

Partner with Jacob Frye (When this creature enters, target player may put Jacob into their hand from their library, then shuffle.)
{1}, {T}: Draw a card, then discard a card. When you discard a creature card this way, target creature you control can't be blocked this turn.

Aven Heartstabber

Flying
As long as there are five or more mana values among cards in your graveyard, this creature gets +2/+2 and has deathtouch.
When this creature dies, mill two cards, then draw a card.

Ravenloft Adventurer

When this creature enters, you take the initiative.
If a creature an opponent controls would die, instead exile it and put a hit counter on it.
Whenever this creature attacks, if you've completed a dungeon, defending player loses 1 life for each card they own in exile with a hit counter on it.

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Royal Assassin

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice this artifact: Draw a card.

Contaminated Aquifer

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

Virtus the Veiled

Partner with Gorm the Great (When this creature enters, target player may put Gorm into their hand from their library, then shuffle.)
Deathtouch
Whenever Virtus deals combat damage to a player, that player loses half their life, rounded up.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Rooftop Assassin

Flash
Flying, lifelink
When this creature enters, destroy target creature an opponent controls that was dealt damage this turn.

Cloak of Mists

Enchant creature
Enchanted creature can't be blocked.

Corrupted Conscience

Enchant creature
You control enchanted creature.
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Murkwater Pathway

Clearwater Pathway

Clearwater Pathway // Murkwater Pathway

Fetid Pools

({T}: Add {U} or {B}.)
This land enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Necrogen Communion

Enchant creature you control
Enchanted creature has toxic 2. (Players dealt combat damage by it also get two poison counters.)
When enchanted creature dies, return that card to the battlefield under your control.

Prosthetic Injector

Equipped creature gets +0/+2 and has toxic 1. (Players dealt combat damage by equipped creature also get a poison counter.)
Equip {1}

Darkslick Shores

This land enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.

Callidus Assassin

Flash
Polymorphine — You may have this creature enter tapped as a copy of any creature on the battlefield, except it has "When this creature enters, destroy up to one other target creature with the same name as this creature."

Thorn of the Black Rose

Deathtouch
When this creature enters, you become the monarch.

Basim Ibn Ishaq

Whenever you cast a historic spell, draw a card. Basim Ibn Ishaq can't be blocked this turn. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic.)
Whenever Basim Ibn Ishaq deals combat damage to a player, put a +1/+1 counter on it.

Escape Detection

Freerunning—Return a blue creature you control to its owner's hand. (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Return target creature to its owner's hand.
Draw a card.

Brotherhood Ambushers

Freerunning {3}{B} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. This artifact deals 1 damage to you.

Jacob Frye

Partner with Evie Frye (When this creature enters, target player may put Evie into their hand from their library, then shuffle.)
Whenever one or more Assassins you control deal combat damage to a player, exile up to one target Assassin card or card with freerunning from your graveyard. If you do, copy it. You may cast the copy.

Genji Glove

Equipped creature has double strike.
Whenever equipped creature attacks, if it's the first combat phase of the turn, untap it. After this phase, there is an additional combat phase.
Equip {3}

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.

Infectious Inquiry

You draw two cards and you lose 2 life. Each opponent gets a poison counter.

Access Tunnel

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

Poison-Blade Mentor

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever this creature attacks, another target Assassin you control gains deathtouch until end of turn.

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.

Darkwater Catacombs

Loyal Inventor

Vigilance
When this creature enters, you may search your library for an artifact card, reveal it, then shuffle. Put that card into your hand if you control an Assassin. Otherwise, put that card on top of your library.

Sunken Ruins

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Shipwreck Marsh

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Dimir Signet

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. This land deals 1 damage to you.

Tainted Strike

Target creature gets +1/+0 and gains infect until end of turn. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Ezio, Blade of Vengeance

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever an Assassin you control deals combat damage to a player, draw a card.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever this Equipment becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Prologue to Phyresis

Each opponent gets a poison counter.
Draw a card.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Swamp

Adaptive Automaton

As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Aspirant's Ascent

Until end of turn, target creature gets +1/+3 and gains flying and toxic 1. (Players dealt combat damage by that creature also get a poison counter.)

Whisper of the Dross

Target creature gets -1/-1 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Dark Ritual

Mask of Riddles

Equipped creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
Whenever equipped creature deals combat damage to a player, you may draw a card.
Equip {2}

Achilles Davenport

Freerunning {U}{B} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Menace (This creature can't be blocked except by two or more creatures.)
Other Assassins you control get +1/+1.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Merciless Harlequin

Freerunning {1}{B} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
When this creature enters, you draw a card and you lose 1 life.

Dimir Aqueduct

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

Interceptor, Shadow's Hound

Menace
Assassins you control have menace.
Whenever you attack with one or more legendary creatures, you may pay {2}{B}. If you do, return this card from your graveyard to the battlefield tapped and attacking.

Arcane Signet

Unstoppable Slasher

Deathtouch
Whenever this creature deals combat damage to a player, they lose half their life, rounded up.
When this creature dies, if it had no counters on it, return it to the battlefield tapped under its owner's control with two stun counters on it.

Watery Grave

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

Mari, the Killing Quill

Whenever a creature an opponent controls dies, exile it with a hit counter on it.
Assassins, Mercenaries, and Rogues you control have deathtouch and "Whenever this creature deals combat damage to a player, you may remove a hit counter from a card that player owns in exile. If you do, draw a card and create two Treasure tokens."

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
This creature can't be blocked.

Sign in Blood

Target player draws two cards and loses 2 life.

Sol Ring

Infernal Grasp

Destroy target creature. You lose 2 life.

Phyresis

Enchant creature
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Vraska's Fall

Each opponent sacrifices a creature or planeswalker of their choice and gets a poison counter.

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Silumgar Assassin

Creatures with power greater than this creature's power can't block it.
Megamorph {2}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When this creature is turned face up, destroy target creature with power 3 or less an opponent controls.

Island

Adrestia

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever Adrestia attacks, if an Assassin crewed it this turn, draw a card. Adrestia becomes an Assassin in addition to its other types until end of turn.
Crew 1

Sky Diamond

This artifact enters tapped.
{T}: Add {U}.

Ramses, Assassin Lord

Deathtouch
Other Assassins you control get +1/+1.
Whenever a player loses the game, if they were attacked this turn by an Assassin you controlled, you win the game.

Brotherhood Spy

At the beginning of combat on your turn, if you control a legendary Assassin, this creature gets +1/+0 until end of turn and can't be blocked this turn.

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Karn's Bastion

{T}: Add {C}.
{4}, {T}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Back in Town

Return X target outlaw creature cards from your graveyard to the battlefield. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)