Rat Out

Up to one target creature gets -1/-1 until end of turn. You create a 1/1 black Rat creature token with "This creature can't block."

Mark of Mutiny

Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)

Trailblazing Historian

Haste
{T}: Another target creature gains haste until end of turn.

Etched Familiar

When Etched Familiar dies, each opponent loses 2 life and you gain 2 life.

Lose Calm

Gain control of target creature until end of turn. Untap that creature. It gains haste and menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

The Beast, Deathless Prince

When you cast this spell, gain control of target creature until end of turn. Untap it. It gains menace and haste until end of turn.
The Beast enters tapped with six stun counters on it. (If it would become untapped, remove a stun counter from it instead.)
Whenever a creature deals combat damage to its owner, untap The Beast and 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.

Stonewright

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Stonewright is paired with another creature, each of those creatures has "{R}: This creature gets +1/+0 until end of turn."

Caught Red-Handed

This spell can't be countered. (This includes by the ward ability.)
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Suspect it. (It has menace and can't block.)

Hired Blade

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

Hell to Pay

Hell to Pay deals X damage to target creature. Create a number of tapped Treasure tokens equal to the amount of excess damage dealt to that creature this way.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Contaminated Bond

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Whenever enchanted creature attacks or blocks, its controller loses 3 life.

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.)

Rakdos Joins Up

When Rakdos Joins Up enters, return target creature card from your graveyard to the battlefield with two additional +1/+1 counters on it.
Whenever a legendary creature you control dies, Rakdos Joins Up deals damage equal to that creature's power to target opponent.

Burakos, Party Leader

Burakos, Party Leader is also a Cleric, Rogue, Warrior, and Wizard.
Whenever Burakos attacks, defending player loses X life and you create X Treasure tokens, where X is the number of creatures in your party.
Choose a Background (You can have a Background as a second commander.)

Khârn the Betrayer

Berzerker — Khârn the Betrayer attacks or blocks each combat if able.
Sigil of Corruption — When you lose control of Khârn the Betrayer, draw two cards.
The Betrayer — If damage would be dealt to Khârn the Betrayer, prevent that damage and an opponent of your choice gains control of it.

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.

Iron Myr

Havoc Devils

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

Eternal Thirst

Enchant creature
Enchanted creature has lifelink and "Whenever a creature an opponent controls dies, put a +1/+1 counter on this creature." (Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Reliquary Tower

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

Akki Ronin

Whenever a Samurai or Warrior you control attacks alone, you may discard a card. If you do, draw a card.

Terminate

Destroy target creature. It can't be regenerated.

Dutiful Attendant

When Dutiful Attendant dies, return another target creature card from your graveyard to your hand.

Rabbit Battery

Haste
Equipped creature gets +1/+1 and has haste.
Reconfigure {R} ({R}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Bond of Passion

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Bond of Passion deals 2 damage to any other target.

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Mountain

Molten Duplication

Create a token that's a copy of target artifact or creature you control, except it's an artifact in addition to its other types. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Charcoal Diamond

Charcoal Diamond enters tapped.
{T}: Add {B}.

Swamp

Binding Negotiation

Target opponent reveals their hand. You may choose a nonland card from it. If you do, they discard it. Otherwise, you may put a face-up exiled card they own into their graveyard.

Assassin Initiate

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

Royal Assassin

Kami's Flare

Kami's Flare deals 3 damage to target creature or planeswalker. Kami's Flare also deals 2 damage to that permanent's controller if you control a modified creature. (Equipment, Auras you control, and counters are modifications.)

Leaden Myr

Liliana's Devotee

Zombies you control get +1/+0.
At the beginning of your end step, if a creature died this turn, you may pay {1}{B}. If you do, create a 2/2 black Zombie creature token.

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Spreading Insurrection

Gain control of target creature you don't control until end of turn. Untap that creature. It gains haste until end of turn.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Firebrand Archer

Whenever you cast a noncreature spell, Firebrand Archer deals 1 damage to each opponent.

Goatnap

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. If that creature is a Goat, it also gets +3/+0 until end of turn.

Command Tower

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

Portent of Betrayal

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Witty Roastmaster

Alliance — Whenever another creature you control enters, Witty Roastmaster deals 1 damage to each opponent.

Xander's Pact

Casualty 2 (As you cast this spell, you may sacrifice a creature with power 2 or greater. When you do, copy this spell.)
Each opponent exiles the top card of their library. You may cast spells from among those cards this turn. If you cast a spell this way, pay life equal to that spell's mana value rather than pay its mana cost.

The Grey Havens

When The Grey Havens enters, scry 1.
{T}: Add {C}.
{T}: Add one mana of any color among legendary creature cards in your graveyard.

Hypnotic Cloud

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Target player discards a card. If this spell was kicked, that player discards three cards instead.

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Highway Robber

When Highway Robber enters, target opponent loses 2 life and you gain 2 life.

Cathartic Reunion

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

Corrupt Court Official

When Corrupt Court Official enters, target opponent discards a card.

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Humble Defector

{T}: Draw two cards. Target opponent gains control of Humble Defector. Activate only during your turn.

Fire Diamond

Fire Diamond enters tapped.
{T}: Add {R}.

Servant of Tymaret

Inspired — Whenever Servant of Tymaret becomes untapped, each opponent loses 1 life. You gain life equal to the life lost this way.
{2}{B}: Regenerate Servant of Tymaret.

Nirkana Assassin

Whenever you gain life, Nirkana Assassin gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Unholy Strength

Enchant creature
Enchanted creature gets +2/+1.

Call for Aid

Gain control of all creatures target opponent controls until end of turn. Untap those creatures. They gain haste until end of turn. You can't attack that player this turn. You can't sacrifice those creatures this turn.

Zulaport Chainmage

Cohort — {T}, Tap an untapped Ally you control: Target opponent loses 2 life.

Undertaker

{B}, {T}, Discard a card: Return target creature card from your graveyard to your hand.

Check for Traps

Target opponent reveals their hand. You choose a nonland card from it. Exile that card. If an instant card or a card with flash is exiled this way, they lose 1 life. Otherwise, you lose 1 life.

Commander's Sphere

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

Virus Beetle

When Virus Beetle enters, each opponent discards a card.

Alexios, Deimos of Kosmos

Trample
Alexios, Deimos of Kosmos attacks each combat if able, can't be sacrificed, and can't attack its owner.
At the beginning of each player's upkeep, that player gains control of Alexios, untaps it, and puts a +1/+1 counter on it. It gains haste until end of turn.