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.)

Red Elemental Blast

Choose one —
• Counter target blue spell.
• Destroy target blue permanent.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

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."

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Rite of the Raging Storm

Creatures named Lightning Rager can't attack you or planeswalkers you control.
At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager. It has trample, haste, and "At the beginning of the end step, sacrifice this creature."

Frontier Warmonger

Whenever one or more creatures attack one of your opponents or a planeswalker they control, those creatures gain menace until end of turn.

Command Beacon

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

Archetype of Aggression

Creatures you control have trample.
Creatures your opponents control lose trample and can't have or gain trample.

Molten Influence

Counter target instant or sorcery spell unless its controller has Molten Influence deal 4 damage to them.

Frenzied Saddlebrute

Haste
All creatures can attack your opponents and planeswalkers your opponents control as though those creatures had haste.

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 artifact: Add one mana of any color.")

Glorious End

End the turn. (Exile all spells and abilities from the stack, including this card. The player whose turn it is discards down to their maximum hand size. Damage wears off, and "this turn" and "until end of turn" effects end.)
At the beginning of your next end step, you lose the game.

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.)

Arcane Signet

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

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.

Burnout

Counter target instant spell if it's blue.
Draw a card at the beginning of the next turn's upkeep.

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Sol Ring

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.)

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Pyroblast

Choose one —
• Counter target spell if it's blue.
• Destroy target permanent if it's blue.

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.)

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Mountain

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.

Bloodmark Mentor

Red creatures you control have first strike.

Blood Moon

Fumiko the Lowblood

Fumiko the Lowblood has bushido X, where X is the number of attacking creatures. (Whenever this creature blocks or becomes blocked, it gets +X/+X until end of turn.)
Creatures your opponents control attack each combat if able.

Court of Embereth

When Court of Embereth enters, you become the monarch.
At the beginning of your upkeep, create a 3/1 red Knight creature token. Then if you're the monarch, Court of Embereth deals X damage to each opponent, where X is the number of creatures you control.