Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Traitorous Blood

Gain control of target creature until end of turn. Untap it. It gains trample and haste until end of turn.

Rakdos Carnarium

Rakdos Carnarium enters tapped.
When Rakdos Carnarium enters, return a land you control to its owner's hand.
{T}: Add {B}{R}.

Polymorphist's Jest

Until end of turn, each creature target player controls loses all abilities and becomes a blue Frog with base power and toughness 1/1.

Helm of Possession

You may choose not to untap Helm of Possession during your untap step.
{2}, {T}, Sacrifice a creature: Gain control of target creature for as long as you control Helm of Possession and Helm of Possession remains tapped.

Grave Betrayal

Whenever a creature you don't control dies, return it to the battlefield under your control with an additional +1/+1 counter on it at the beginning of the next end step. That creature is a black Zombie in addition to its other colors and types.

Sign in Blood

Target player draws two cards and loses 2 life.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Command Tower

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

Besmirch

Until end of turn, gain control of target creature and it gains haste. Untap and goad that creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Hijack

Gain control of target artifact or creature until end of turn. Untap it. It gains haste until end of turn.

Insurrection

Untap all creatures and gain control of them until end of turn. They gain haste until end of turn.

Mob Rule

Choose one —
• Gain control of all creatures with power 4 or greater until end of turn. Untap those creatures. They gain haste until end of turn.
• Gain control of all creatures with power 3 or less until end of turn. Untap those creatures. They gain haste until end of turn.

Captivating Glance

Enchant creature
At the beginning of your end step, clash with an opponent. If you win, gain control of enchanted creature. Otherwise, that player gains control of enchanted creature. (Each clashing player reveals the top card of their library, then puts that card on the top or bottom. A player wins if their card had a higher mana value.)

Conquering Manticore

Flying
When Conquering Manticore enters, gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Acquire

Search target opponent's library for an artifact card and put that card onto the battlefield under your control. Then that player shuffles.

Slave of Bolas

Gain control of target creature. Untap that creature. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.

Sepulchral Primordial

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
When Sepulchral Primordial enters, for each opponent, you may put up to one target creature card from that player's graveyard onto the battlefield under your control.

Visage of Bolas

When Visage of Bolas enters, you may search your library and/or graveyard for a card named Nicol Bolas, the Deceiver, reveal it, and put it into your hand. If you search your library this way, shuffle.
{T}: Add {U}, {B}, or {R}.

Reins of Power

Untap all creatures you control and all creatures target opponent controls. You and that opponent each gain control of all creatures the other controls until end of turn. Those creatures gain haste until end of turn.

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Control Magic

Enchant creature
You control enchanted creature.

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.)

Traitorous Instinct

Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gets +2/+0 and gains haste.

Rise of the Dark Realms

Put all creature cards from all graveyards onto the battlefield under your control.

Captivating Crew

{3}{R}: Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn. Activate only as a sorcery.

Steal Enchantment

Enchant enchantment
You control enchanted enchantment.

Grab the Reins

Choose one —
• Until end of turn, you gain control of target creature and it gains haste.
• Sacrifice a creature. Grab the Reins deals damage equal to that creature's power to any target.
Entwine {2}{R} (Choose both if you pay the entwine cost.)

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Steal Artifact

Enchant artifact
You control enchanted artifact.

Nexus of Fate

Take an extra turn after this one.
If Nexus of Fate would be put into a graveyard from anywhere, reveal Nexus of Fate and shuffle it into its owner's library instead.

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.

Word of Seizing

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Untap target permanent and gain control of it until end of turn. It gains haste until end of turn.

Desertion

Counter target spell. If an artifact or creature spell is countered this way, put that card onto the battlefield under your control instead of into its owner's graveyard.

Spinal Embrace

Cast this spell only during combat.
Untap target creature you don't control and gain control of it. It gains haste until end of turn. At the beginning of the next end step, sacrifice it. If you do, you gain life equal to its toughness.

Dimir Aqueduct

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

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Mass Mutiny

For each opponent, gain control of up to one target creature that player controls until end of turn. Untap those creatures. They gain haste until end of turn.

Zealous Conscripts

Haste
When Zealous Conscripts enters, gain control of target permanent until end of turn. Untap that permanent. It gains haste until end of turn.

Sol Ring

Night's Whisper

Chamber of Manipulation

Enchant land
Enchanted land has "{T}, Discard a card: Gain control of target creature until end of turn."

Agent of Treachery

When Agent of Treachery enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Act of Aggression

({R/P} can be paid with either {R} or 2 life.)
Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Izzet Signet

Dimir Signet

Thalakos Deceiver

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever Thalakos Deceiver attacks and isn't blocked, you may sacrifice it. If you do, gain control of target creature. (This effect lasts indefinitely.)

Tibalt, the Fiend-Blooded

+1: Draw a card, then discard a card at random.
−4: Tibalt, the Fiend-Blooded deals damage equal to the number of cards in target player's hand to that player.
−6: Gain control of all creatures until end of turn. Untap them. They gain haste until end of turn.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Bribery

Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Carrion Feeder

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

Viscera Seer

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Rakdos Signet

Obelisk of Grixis

Sadistic Hypnotist

Sacrifice a creature: Target player discards two cards. Activate only as a sorcery.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Grimgrin, Corpse-Born

Grimgrin, Corpse-Born enters tapped and doesn't untap during your untap step.
Sacrifice another creature: Untap Grimgrin and put a +1/+1 counter on it.
Whenever Grimgrin attacks, destroy target creature defending player controls, then put a +1/+1 counter on Grimgrin.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control Roil Elemental.

Lord of Tresserhorn

When Lord of Tresserhorn enters, you lose 2 life, you sacrifice two creatures, and target opponent draws two cards.
{B}: Regenerate Lord of Tresserhorn.

Marchesa, the Black Rose

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Other creatures you control have dethrone.
Whenever a creature you control with a +1/+1 counter on it dies, return that card to the battlefield under your control at the beginning of the next end step.

Polymorph

Destroy target creature. It can't be regenerated. Its controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield, then shuffles all other cards revealed this way into their library.

Dominating Licid

{1}{U}{U}, {T}: Dominating Licid loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {U} to end this effect.
You control enchanted creature.

Blood Artist

Whenever Blood Artist or another creature dies, target player loses 1 life and you gain 1 life.

Vial Smasher the Fierce

Whenever you cast your first spell each turn, choose an opponent at random. Vial Smasher the Fierce deals damage equal to that spell's mana value to that player or a planeswalker that player controls.
Partner (You can have two commanders if both have partner.)

Volition Reins

Enchant permanent
When Volition Reins enters, if enchanted permanent is tapped, untap it.
You control enchanted permanent.

Blind with Anger

Untap target nonlegendary creature and gain control of it until end of turn. That creature gains haste until end of turn.

Memnarch

{1}{U}{U}: Target permanent becomes an artifact in addition to its other types. (This effect lasts indefinitely.)
{3}{U}: Gain control of target artifact. (This effect lasts indefinitely.)

Turn to Frog

Until end of turn, target creature loses all abilities and becomes a blue Frog with base power and toughness 1/1.