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.)

Titan Hunter

At the beginning of each player's end step, if no creatures died this turn, Titan Hunter deals 4 damage to that player.
{1}{B}, Sacrifice a creature: You gain 4 life.

Urza's Rage

Kicker {8}{R} (You may pay an additional {8}{R} as you cast this spell.)
This spell can't be countered.
Urza's Rage deals 3 damage to any target. If this spell was kicked, instead it deals 10 damage to that permanent or player and the damage can't be prevented.

Viashino Heretic

{1}{R}, {T}: Destroy target artifact. Viashino Heretic deals damage to that artifact's controller equal to the artifact's mana value.

Coalition Relic

{T}: Add one mana of any color.
{T}: Put a charge counter on Coalition Relic.
At the beginning of your first main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.

Terminate

Destroy target creature. It can't be regenerated.

Anathemancer

When Anathemancer enters, it deals damage to target player equal to the number of nonbasic lands that player controls.
Unearth {5}{B}{R} ({5}{B}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Havoc Festival

Players can't gain life.
At the beginning of each player's upkeep, that player loses half their life, rounded up.

Lightning Skelemental

Trample, haste
Whenever Lightning Skelemental deals combat damage to a player, that player discards two cards.
At the beginning of the end step, sacrifice Lightning Skelemental.

Sulfuric Vortex

At the beginning of each player's upkeep, Sulfuric Vortex deals 2 damage to that player.
If a player would gain life, that player gains no life instead.

Fellwar Stone

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

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Browbeat

Any player may have Browbeat deal 5 damage to them. If no one does, target player draws three cards.

Boil

Scab-Clan Berserker

Haste
Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever an opponent casts a noncreature spell, if Scab-Clan Berserker is renowned, Scab-Clan Berserker deals 2 damage to that player.

Charcoal Diamond

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

Sol Ring

Syphon Mind

Each other player discards a card. You draw a card for each card discarded this way.

Bitter Feud

As Bitter Feud enters, choose two players.
If a source controlled by one of the chosen players would deal damage to the other chosen player or a permanent that player controls, that source deals double that damage to that player or permanent instead.

Spellshock

Whenever a player casts a spell, Spellshock deals 2 damage to that player.

Clackbridge Troll

Trample, haste
When Clackbridge Troll enters, target opponent creates three 0/1 white Goat creature tokens.
At the beginning of combat on your turn, any opponent may sacrifice a creature. If a player does, tap Clackbridge Troll, you gain 3 life, and you draw a card.

Dictate of the Twin Gods

Flash
If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Chandra's Ignition

Target creature you control deals damage equal to its power to each other creature and each opponent.

Quakebringer

Your opponents can't gain life.
At the beginning of your upkeep, Quakebringer deals 2 damage to each opponent. This ability triggers only if Quakebringer is on the battlefield or if Quakebringer is in your graveyard and you control a Giant.
Foretell {2}{R}{R}

Slagstorm

Choose one —
• Slagstorm deals 3 damage to each creature.
• Slagstorm deals 3 damage to each player.

Breaking Point

Any player may have Breaking Point deal 6 damage to them. If no one does, destroy all creatures. Creatures destroyed this way can't be regenerated.

Obosh, the Preypiercer

Companion — Your starting deck contains only cards with odd mana values and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Liquimetal Torque

{T}: Add {C}.
{T}: Target nonland permanent becomes an artifact in addition to its other types until end of turn.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Rain of Gore

If a spell or ability would cause its controller to gain life, that player loses that much life instead.

Fire Diamond

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

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Hellish Rebuke

Until end of turn, permanents your opponents control gain "When this permanent deals damage to the player who cast Hellish Rebuke, sacrifice this permanent. You lose 2 life."

Prismatic Lens

{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Lightning Reaver

Haste; fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Lightning Reaver deals combat damage to a player, put a charge counter on it.
At the beginning of your end step, Lightning Reaver deals damage equal to the number of charge counters on it to each opponent.

Malignus

Malignus's power and toughness are each equal to half the highest life total among your opponents, rounded up.
Damage that would be dealt by Malignus can't be prevented.

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Hour of Devastation

All creatures lose indestructible until end of turn. Hour of Devastation deals 5 damage to each creature and each non-Bolas planeswalker.

Blood Moon

Pain Magnification

Whenever an opponent is dealt 3 or more damage by a single source, that player discards a card.

Rakdos Signet

Arcbond

Choose target creature. Whenever that creature is dealt damage this turn, it deals that much damage to each other creature and each player.

Arcane Signet

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

Breath of Malfegor

Breath of Malfegor deals 5 damage to each opponent.

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Heartless Hidetsugu

{T}: Heartless Hidetsugu deals damage to each player equal to half that player's life total, rounded down.

Angrath's Marauders

If a source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth, Maw of Flames attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.