Necrotic Ooze

As long as this creature is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Elder Brain

Menace
Whenever this creature attacks a player, exile all cards from that player's hand, then they draw that many cards. You may play lands and cast spells from among the exiled cards for as long as they remain exiled. If you cast a spell this way, you may spend mana as though it were mana of any color to cast it.

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.)

Chain Assassination

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.)
Destroy target creature. If another creature died this turn, draw a card.

Briarblade Adept

Whenever this creature attacks, target creature an opponent controls gets -1/-1 until end of turn.
Encore {3}{B} ({3}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Desmond Miles

Menace
Desmond Miles gets +1/+0 for each other Assassin you control and each Assassin card in your graveyard.
Whenever Desmond Miles deals combat damage to a player, surveil X, where X is the amount of damage it dealt to that player.

Wander in Death

Return up to two target creature cards from your graveyard to your hand.
Cycling {2} ({2}, Discard this card: Draw a card.)

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Tymaret, Chosen from Death

Tymaret's toughness is equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
{1}{B}: Exile up to two target cards from graveyards. You gain 1 life for each creature card exiled this way.

Phantom Blade

When this Equipment enters, attach it to up to one target creature you control. Destroy up to one other target creature.
Equipped creature gets +1/+1 and has menace. (It can't be blocked except by two or more creatures.)
Equip {2}

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Insatiable Hemophage

Mutate {2}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Deathtouch
Whenever this creature mutates, each opponent loses X life and you gain X life, where X is the number of times this creature has mutated.

Orochi Soul-Reaver

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token and manifest the top card of that player's library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

Bloodborn Scoundrels

Assist (Another player can pay up to {5} of this spell's cost.)
When this creature enters, target opponent loses 2 life and you gain 2 life.

Warlock Class

(Gain the next level as a sorcery to add its ability.)
At the beginning of your end step, if a creature died this turn, each opponent loses 1 life.
{1}{B}: Level 2
When this Class becomes level 2, look at the top three cards of your library. Put one of them into your hand and the rest into your graveyard.
{6}{B}: Level 3
At the beginning of your end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Drossclaw

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Whenever equipped creature attacks, each opponent loses 1 life.
Equip {2}

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.

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."

Wasteland Raider

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
When this creature enters, each player sacrifices a creature of their choice.

Royal Assassin

Illicit Masquerade

Flash
When this enchantment enters, put an impostor counter on each creature you control.
Whenever a creature you control with an impostor counter on it dies, exile it. Return up to one other target creature card from your graveyard to the battlefield.

Join the Dead

Target creature gets -5/-5 until end of turn.
Descend 4 — That creature gets -10/-10 until end of turn instead if there are four or more permanent cards in your graveyard.

Macabre Reconstruction

This spell costs {2} less to cast if a creature card was put into your graveyard from anywhere this turn.
Return up to two target creature cards from your graveyard to your hand.

The Revelations of Ezio

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target tapped creature an opponent controls.
II — Whenever an Assassin you control attacks this turn, put a +1/+1 counter on it.
III — Return target Assassin creature card from your graveyard to the battlefield with an additional +1/+1 counter on it.

Murder

Roshan, Hidden Magister

Other creatures you control are Assassins in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
Face-down creatures you control have menace.
Whenever a permanent you control is turned face up, you draw a card and you lose 1 life.

Vraska's Finisher

When this creature enters, destroy target creature or planeswalker an opponent controls that was dealt damage this turn.

Skulking Killer

When this creature enters, target creature an opponent controls gets -2/-2 until end of turn if that opponent controls no other creatures.

Supernatural Stamina

Until end of turn, target creature gets +2/+0 and gains "When this creature dies, return it to the battlefield tapped under its owner's control."

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.

Consuming Corruption

Consuming Corruption deals X damage to target creature or planeswalker and you gain X life, where X is the number of Swamps you control.

Danse Macabre

Each player sacrifices a nontoken creature of their choice. Roll a d20 and add the toughness of the creature you sacrificed this way.
1—14 | Return a creature card put into a graveyard this way to the battlefield under your control.
15+ | Return up to two creature cards put into graveyards this way to the battlefield under your control.

Vault Plunderer

When this creature enters, target player draws a card and loses 1 life.

Lawless Broker

When this creature dies, put a +1/+1 counter on target creature you control.

Nekrataal

First strike
When this creature enters, destroy target nonartifact, nonblack creature. That creature can't be regenerated.

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Executioner's Capsule

{1}{B}, {T}, Sacrifice this artifact: Destroy target nonblack creature.

Hagra Sharpshooter

{4}{B}: Target creature gets -1/-1 until end of turn.

Black Market

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Forever Young

Put any number of target creature cards from your graveyard on top of your library.
Draw a card.

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.

Forsaken Miner

This creature can't block.
Whenever you commit a crime, you may pay {B}. If you do, return this card from your graveyard to the battlefield. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Frogtosser Banneret

Haste
Goblin spells and Rogue spells you cast cost {1} less to cast.

Spymaster's Vault

This land enters tapped unless you control a Swamp.
{T}: Add {B}.
{B}, {T}: Target creature you control connives X, where X is the number of creatures that died this turn. (Draw X cards, then discard X cards. Put a +1/+1 counter on that creature for each nonland card discarded this way.)

Hired Blade

Flash (You may cast this spell any time you could cast an instant.)

Alley Assailant

This creature enters tapped.
Disguise {4}{B}{B} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When this creature is turned face up, target opponent loses 3 life and you gain 3 life.

Scurrilous Sentry

Menace
Whenever this creature enters or attacks, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Rooftop Assassin

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

Petty Larceny

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.)
Look at the top two cards of target opponent's library and exile those cards face down. You may play those cards for as long as they remain exiled, and mana of any type can be spent to cast them. Create a Treasure token.

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Assassin Initiate

{1}: This creature gains your choice of flying, deathtouch, or lifelink until end of turn.

Conspiracy

As this enchantment enters, choose a creature type.
Creatures you control are the chosen type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

V.A.T.S.

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Choose any number of target creatures with equal toughness. Destroy the chosen creatures.

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.

Swamp

Hidden Blade

Flash
When this Equipment enters, attach it to target creature you control. If that creature is an Assassin, it gains deathtouch until end of turn.
Equipped creature gets +1/+0 and has first strike.
Equip {2}

Hemlock Vial

When this artifact enters, you draw a card and you lose 1 life.
{B}, {T}, Sacrifice this artifact: Each equipped creature and Equipment you control gains deathtouch until end of turn.

Soul Conduit

{6}, {T}: Two target players exchange life totals.

Butch DeLoria, Tunnel Snake

Menace (This creature can't be blocked except by two or more creatures.)
Tunnel Snakes Rule! — Whenever Butch DeLoria attacks, it gets +1/+1 until end of turn for each other Rogue and/or Snake you control.
{1}{B}: Put a menace counter on another target creature. It becomes a Rogue in addition to its other types.

Thrill-Kill Assassin

Deathtouch
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Lethal Scheme

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy target creature or planeswalker. Each creature that convoked this spell connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Lethal Throwdown

As an additional cost to cast this spell, sacrifice a creature or sacrifice a modified creature. (Equipment, Auras you control, and counters are modifications.)
Destroy target creature or planeswalker. If the modified creature was sacrificed, draw a card.

Hollow Marauder

This spell costs {1} less to cast for each creature card in your graveyard.
Flying
When this creature enters, any number of target opponents each discard a card. For each of those opponents who didn't discard a card with mana value 4 or greater, draw a card.

Restart Sequence

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.)
Return target creature card from your graveyard to the battlefield.

Lead Pipe

Equipped creature gets +2/+0.
Whenever equipped creature dies, each opponent loses 1 life.
{2}, Sacrifice this Equipment: Draw a card.
Equip {2}

Orzhov Euthanist

Haunt (When this creature dies, exile it haunting target creature.)
When this creature enters or the creature it haunts dies, destroy target creature that was dealt damage this turn.