Overpowering Attack

Freerunning {2}{R} (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Untap all creatures you control that attacked this turn. If it's your main phase, there is an additional combat phase after this phase, followed by an additional main phase.

Cover of Darkness

As this enchantment enters, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Elegant Parlor

({T}: Add {R} or {W}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Talisman of Indulgence

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

Aya of Alexandria

Menace, lifelink
Whenever a historic creature you control deals combat damage to a player, create a 1/1 black Assassin creature token with menace. (Artifacts, legendaries, and Sagas are historic.)

Guildsworn Prowler

Deathtouch
When this creature dies, if it wasn't blocking, draw a card.

Kassandra, Eagle Bearer

Haste
When Kassandra enters, search your graveyard, hand, and library for a card named The Spear of Leonidas, put it onto the battlefield, then shuffle.
Whenever a creature you control with a legendary Equipment attached to it deals combat damage to a player, draw a card.

Smoldering Marsh

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

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Plains

Olivia, Opulent Outlaw

Flying, lifelink
Whenever one or more outlaws you control deal combat damage to a player, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
{3}, Sacrifice two Treasures: Put two +1/+1 counters on each creature you control. Activate only as a sorcery.

Command Tower

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

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.

Savai Triome

({T}: Add {R}, {W}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Vein Ripper

Flying
Ward—Sacrifice a creature.
Whenever a creature dies, target opponent loses 2 life and you gain 2 life.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Anointed Procession

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.

Ruthless Lawbringer

When this creature enters, you may sacrifice another creature. When you do, destroy target nonland permanent.

Hour of Reckoning

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 all nontoken creatures.

Altaïr Ibn-La'Ahad

First strike
Whenever Altaïr attacks, exile up to one target Assassin creature card from your graveyard with a memory counter on it. Then for each creature card you own in exile with a memory counter on it, create a tapped and attacking token that's a copy of it. Exile those tokens at end of combat.

Vault of the Archangel

{T}: Add {C}.
{2}{W}{B}, {T}: Creatures you control gain deathtouch and lifelink until end of turn.

Boros Signet

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Thorn of the Black Rose

Deathtouch
When this creature enters, you become the monarch.

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.

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.)

Talisman of Hierarchy

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

Swamp

Mountain

Mondrak, Glory Dominus

If one or more tokens would be created under your control, twice that many of those tokens are created instead.
{1}{W/P}{W/P}, Sacrifice two other artifacts and/or creatures: Put an indestructible counter on Mondrak. ({W/P} can be paid with either {W} or 2 life.)

Haunted Ridge

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

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Vault of Champions

This land enters tapped unless you have two or more opponents.
{T}: Add {W} or {B}.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Nekrataal

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

Orzhov Signet

Mirkwood Bats

Flying
Whenever you create or sacrifice a token, each opponent loses 1 life.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Clifftop Retreat

This land enters tapped unless you control a Mountain or a Plains.
{T}: Add {R} or {W}.

Luxury Suite

This land enters tapped unless you have two or more opponents.
{T}: Add {B} or {R}.

Unscrupulous Contractor

When this creature enters, you may sacrifice a creature. When you do, target player draws two cards and loses 2 life.
Plot {2}{B} (You may pay {2}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Layla Hassan

First strike
When Layla Hassan enters and whenever one or more Assassins you control deal combat damage to a player, return target historic card from your graveyard to your hand.

Garza's Assassin

Sacrifice this creature: Destroy target nonblack creature.
Recover—Pay half your life, rounded up. (When another creature is put into your graveyard from the battlefield, you may pay half your life, rounded up. If you do, return this card from your graveyard to your hand. Otherwise, exile this card.)

Roaming Throne

Ward {2}
As this creature enters, choose a creature type.
This creature is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Isolated Chapel

This land enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Brotherhood Patriarch

When this creature dies, each opponent loses 2 life and you gain 2 life.

Brotherhood Headquarters

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast an Assassin spell or a spell that has freerunning, or to activate an ability of an Assassin source.

Entomb

Search your library for a card, put that card into your graveyard, then shuffle.

Rakdos Signet

Spectator Seating

This land enters tapped unless you have two or more opponents.
{T}: Add {R} or {W}.

Big Game Hunter

When this creature enters, destroy target creature with power 4 or greater. It can't be regenerated.
Madness {B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Arbaaz Mir

Whenever Arbaaz Mir or another nontoken historic permanent you control enters, Arbaaz Mir deals 1 damage to each opponent and you gain 1 life. (Artifacts, legendaries, and Sagas are historic.)

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."

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

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.)

Undercity Eliminator

When this creature enters, you may sacrifice an artifact or creature. When you do, exile target creature an opponent controls.

Sundown Pass

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

The Master, Multiplied

Myriad
The "legend rule" doesn't apply to creature tokens you control.
Triggered abilities you control can't cause you to sacrifice or exile creature tokens you control.

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.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Lightning Greaves

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

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.

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Warleader's Call

Creatures you control get +1/+1.
Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Raucous Theater

({T}: Add {B} or {R}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Arno Dorian

Deathtouch
Other Assassins you control get +2/+0.
Disguise {B}{R} (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.)

Shadowy Backstreet

({T}: Add {W} or {B}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Nomad Outpost

This land enters tapped.
{T}: Add {R}, {W}, or {B}.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Haystack

{2}, {T}: Target creature you control phases out. (Treat it and anything attached to it as though they don't exist until your next turn.)

The Spear of Leonidas

Whenever equipped creature attacks, choose one —
• Bull Rush — It gains double strike until end of turn.
• Summon — Create Phobos, a legendary 3/2 red Horse creature token.
• Revelation — Discard two cards, then draw two cards.
Equip {2}

Arcane Signet

Talisman of Conviction

{T}: Add {C}.
{T}: Add {R} or {W}. This artifact deals 1 damage to you.

Murderous Redcap

When this creature enters, it deals damage equal to its power to any target.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Sol Ring

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.

Relentless Assault

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.