Invert Polarity

Choose target spell, then flip a coin. If you win the flip, gain control of that spell and you may choose new targets for it. If you lose the flip, counter that spell.

Stormcarved Coast

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

Firkraag, Cunning Instigator

Flying, haste
Whenever one or more Dragons you control attack an opponent, goad target creature that player controls.
Whenever a creature deals combat damage to one of your opponents, if that creature had to attack this combat, you put a +1/+1 counter on Firkraag and you draw a card.

Shiny Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Carnelian Orb of Dragonkind

{T}: Add {R}. If that mana is spent on a Dragon creature spell, it gains haste until end of turn.

Goblin Spymaster

First strike
At the beginning of each opponent's end step, that player creates a 1/1 red Goblin creature token with "Creatures you control attack each combat if able."

Life of the Party

First strike, trample, haste
Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of creatures you control.
When this creature enters, if it's not a token, each opponent creates a token that's a copy of it. The tokens are goaded for the rest of the game. (They attack each combat if able and attack a player other than you if able.)

Goblin

Creatures you control attack each combat if able.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Midnight Clock

{T}: Add {U}.
{2}{U}: Put an hour counter on this artifact.
At the beginning of each upkeep, put an hour counter on this artifact.
When the twelfth hour counter is put on this artifact, shuffle your hand and graveyard into your library, then draw seven cards. Exile this artifact.

Mocking Doppelganger

Flash
You may have this creature enter as a copy of a creature an opponent controls, except it has "Other creatures with the same name as this creature are goaded." (They attack each combat if able and attack a player other than you if able.)

Arcane Signet

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

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Gold

Sacrifice this token: Add one mana of any color.

Commander's Sphere

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

Sol Ring

Copy

(This token can be used to represent a token that's a copy of a permanent.)

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Illusionist's Gambit

Cast this spell only during the declare blockers step on an opponent's turn.
Remove all attacking creatures from combat and untap them. After this phase, there is an additional combat phase. Each of those creatures attacks that combat if able. They can't attack you or planeswalkers you control that combat.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Counterspell

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Territorial Hellkite

Flying, haste
At the beginning of combat on your turn, choose an opponent at random that this creature didn't attack during your last combat. This creature attacks that player this combat if able. If you can't choose an opponent this way, tap this creature.

Curiosity

Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Bloodthirsty Blade

Equipped creature gets +2/+0 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
{1}: Attach this Equipment to target creature an opponent controls. Activate only as a sorcery.

Disrupt Decorum

Goad all creatures you don't control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Fellwar Stone

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

Keiga, the Tide Star

Flying
When Keiga dies, gain control of target creature.

Training Center

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

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Reliquary Tower

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

Agitator Ant

At the beginning of your end step, each player may put two +1/+1 counters on a creature they control. Goad each creature that had counters put on it this way. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Mountain

Curse of the Nightly Hunt

Enchant player
Creatures enchanted player controls attack each combat if able.

Mana Geyser

Add {R} for each tapped land your opponents control.

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.)

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Geode Rager

First strike
Landfall — Whenever a land you control enters, goad each creature target player controls. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Baeloth Barrityl, Entertainer

Creatures your opponents control with power less than Baeloth Barrityl's power are goaded. (They attack each combat if able and attack a player other than you if able.)
Whenever a goaded attacking or blocking creature dies, you create a Treasure token.
Choose a Background (You can have a Background as a second commander.)

Spectacular Showdown

Put a double strike counter on target creature, then goad each creature that had a double strike counter put on it this way. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)
Overload {4}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Curse of Opulence

Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this token: Add one mana of any color.")

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Dragonstorm Globe

Each Dragon you control enters with an additional +1/+1 counter on it.
{T}: Add one mana of any color.

Chaos Dragon

Flying, haste
This creature attacks each combat if able.
At the beginning of combat on your turn, each player rolls a d20. If one or more opponents had the highest result, this creature can't attack those players or planeswalkers they control this combat.

Ganax, Astral Hunter

Flying
Whenever Ganax or another Dragon you control enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
Choose a Background (You can have a Background as a second commander.)

Izzet Boilerworks

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

Lozhan, Dragons' Legacy

Flying
Whenever you cast an Adventure or Dragon spell, Lozhan deals damage equal to that spell's mana value to any target that isn't a commander.

Aetherize

Return all attacking creatures to their owner's hand.

Izzet Signet

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Hot Pursuit

When this enchantment enters, suspect target creature an opponent controls. As long as this enchantment remains on the battlefield, that creature is also goaded.
At the beginning of combat on your turn, if two or more players have lost the game, gain control of all goaded and/or suspected creatures until end of turn. Untap them. They gain haste until end of turn.

Negate

Komainu Battle Armor

Menace
Equipped creature gets +2/+2 and has menace.
Whenever this creature or equipped creature deals combat damage to a player, goad each creature that player controls.
Reconfigure {4} ({4}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Laser Screwdriver

{T}: Add one mana of any color.
{1}, {T}: Tap target artifact.
{2}, {T}: Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
{3}, {T}: Goad target creature. (Until your next turn, it attacks each combat if able and attacks a player other than you if able.)

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Public Enemy

Enchant creature
All creatures attack enchanted creature's controller each combat if able.
When enchanted creature dies, draw a card.

Mox Jasper

{T}: Add one mana of any color. Activate only if you control a Dragon.

The Sound of Drums

Enchant creature
Enchanted creature is goaded.
If enchanted creature would deal combat damage to a permanent or player, it deals double that damage instead.
{2}{R}: Return this card from your graveyard to your hand.

Coronation of Chaos

Up to three target creatures can't block this turn. Goad them. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Bothersome Quasit

Menace
Goaded creatures your opponents control can't block.
Whenever you cast a noncreature spell, goad target creature an opponent controls. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Island

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Boar

Command Beacon

{T}: Add {C}.
{T}, Sacrifice this land: Put your commander into your hand from the command zone.

Vengeful Ancestor

Flying
Whenever this creature enters or attacks, goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)
Whenever a goaded creature attacks, it deals 1 damage to its controller.

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.

Alexios, Deimos of Kosmos

Trample
Alexios 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.

Command Tower

Ruby Medallion

Red spells you cast cost {1} less to cast.

Thought Vessel

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.)

Red Death, Shipwrecker

Alluring Eyes — {T}: Goad target creature an opponent controls. That player draws a card. You add {R}. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Frostboil Snarl

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