Electropotence

Whenever a creature you control enters, you may pay {2}{R}. If you do, that creature deals damage equal to its power to any target.

Acidic Soil

Acidic Soil deals damage to each player equal to the number of lands they control.

Tome of Legends

Tome of Legends enters with a page counter on it.
Whenever your commander enters or attacks, put a page counter on Tome of Legends.
{1}, {T}, Remove a page counter from Tome of Legends: Draw a card.

Seasoned Pyromancer

When Seasoned Pyromancer enters, discard two cards, then draw two cards. For each nonland card discarded this way, create a 1/1 red Elemental creature token.
{3}{R}{R}, Exile Seasoned Pyromancer from your graveyard: Create two 1/1 red Elemental creature tokens.

Ash Zealot

First strike, haste
Whenever a player casts a spell from a graveyard, Ash Zealot deals 3 damage to that player.

Magus of the Moon

Norin the Wary

When a player casts a spell or a creature attacks, exile Norin the Wary. Return it to the battlefield under its owner's control at the beginning of the next end step.

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.

Chandra, Roaring Flame

+1: Chandra, Roaring Flame deals 2 damage to target player or planeswalker.
−2: Chandra, Roaring Flame deals 2 damage to target creature.
−7: Chandra, Roaring Flame deals 6 damage to each opponent. Each player dealt damage this way gets an emblem with "At the beginning of your upkeep, this emblem deals 3 damage to you."

Chandra, Fire of Kaladesh

Whenever you cast a red spell, untap Chandra, Fire of Kaladesh.
{T}: Chandra, Fire of Kaladesh deals 1 damage to target player or planeswalker. If Chandra has dealt 3 or more damage this turn, exile her, then return her to the battlefield transformed under her owner's control.

Chandra, Fire of Kaladesh // Chandra, Roaring Flame

Feldon of the Third Path

{2}{R}, {T}: Create a token that's a copy of target creature card in your graveyard, except it's an artifact in addition to its other types. It gains haste. Sacrifice it at the beginning of the next end step.

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.

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."

Firebrand Archer

Whenever you cast a noncreature spell, this creature deals 1 damage to each opponent.

Sizzling Soloist

Alliance — Whenever another creature you control enters, target creature an opponent controls can't block this turn. If this is the second time this ability has resolved this turn, that creature attacks during its controller's next combat phase if able.

Mana Echoes

Whenever a creature enters, you may add an amount of {C} equal to the number of creatures you control that share a creature type with it.

Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Young Pyromancer

Whenever you cast an instant or sorcery spell, create a 1/1 red Elemental creature token.

Reckless Fireweaver

Whenever an artifact you control enters, Reckless Fireweaver deals 1 damage to each opponent.

Rose Room Treasurer

Alliance — Whenever another creature you control enters, create a Treasure token if this is the first or second time this ability has resolved this turn. Otherwise, you may pay {X}. When you do, Rose Room Treasurer deals X damage to any target.

Terror of the Peaks

Flying
Spells your opponents cast that target Terror of the Peaks cost an additional 3 life to cast.
Whenever another creature you control enters, Terror of the Peaks deals damage equal to that creature's power to any target.

Witty Roastmaster

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

Smuggler's Copter

Flying
Whenever Smuggler's Copter attacks or blocks, you may draw a card. If you do, discard a card.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Ogre Battledriver

Whenever another creature you control enters, that creature gets +2/+0 and gains haste until end of turn. (It can attack and {T} this turn.)

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.

Genesis Chamber

Whenever a nontoken creature enters, if Genesis Chamber is untapped, that creature's controller creates a 1/1 colorless Myr artifact creature token.

Magus of the Wheel

{1}{R}, {T}, Sacrifice Magus of the Wheel: Each player discards their hand, then draws seven cards.

Pyrohemia

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pyrohemia.
{R}: Pyrohemia deals 1 damage to each creature and each player.

Fiery Confluence

Choose three. You may choose the same mode more than once.
• Fiery Confluence deals 1 damage to each creature.
• Fiery Confluence deals 2 damage to each opponent.
• Destroy target artifact.

Reinforced Ronin

Haste
At the beginning of your end step, return Reinforced Ronin to its owner's hand.
Channel — {1}{R}, Discard Reinforced Ronin: 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.

Pyrostatic Pillar

Whenever a player casts a spell with mana value 3 or less, Pyrostatic Pillar deals 2 damage to that player.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Guttersnipe

Whenever you cast an instant or sorcery spell, this creature deals 2 damage to each opponent.

In the Web of War

Whenever a creature you control enters, it gets +2/+0 and gains haste until end of turn.

Mirror March

Whenever a nontoken creature you control enters, flip a coin until you lose a flip. For each flip you won, create a token that's a copy of that creature. Those tokens gain haste. Exile them at the beginning of the next end step.

Aether Sting

Whenever an opponent casts a creature spell, Aether Sting deals 1 damage to that player.

Furnace of Rath

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

Imperial Recruiter

When Imperial Recruiter enters, search your library for a creature card with power 2 or less, reveal it, put it into your hand, then shuffle.

Magmatic Channeler

As long as there are four or more instant and/or sorcery cards in your graveyard, Magmatic Channeler gets +3/+1.
{T}, Discard a card: Exile the top two cards of your library, then choose one of them. You may play that card this turn.

Spellshock

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

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.

Lambholt Ravager

Whenever you cast a noncreature spell, Lambholt Ravager deals 2 damage to each opponent.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Lambholt Raconteur

Whenever you cast a noncreature spell, Lambholt Raconteur deals 1 damage to each opponent.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Lambholt Raconteur // Lambholt Ravager

Grim Lavamancer

{R}, {T}, Exile two cards from your graveyard: Grim Lavamancer deals 2 damage to any target.

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Hanweir Garrison

Whenever Hanweir Garrison attacks, create two 1/1 red Human creature tokens that are tapped and attacking.
(Melds with Hanweir Battlements.)

Roiling Vortex

At the beginning of each player's upkeep, Roiling Vortex deals 1 damage to them.
Whenever a player casts a spell, if no mana was spent to cast that spell, Roiling Vortex deals 5 damage to that player.
{R}: Your opponents can't gain life this turn.

Vigilante Justice

Whenever a Human you control enters, Vigilante Justice deals 1 damage to any target.

Angel's Tomb

Whenever a creature you control enters, you may have Angel's Tomb become a 3/3 white Angel artifact creature with flying until end of turn.

Stensia Uprising

At the beginning of your end step, create a 1/1 red Human creature token. Then if you control exactly thirteen permanents, you may sacrifice Stensia Uprising. When you do, it deals 7 damage to any target.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Chandra, Torch of Defiance

+1: Exile the top card of your library. You may cast that card. If you don't, Chandra, Torch of Defiance deals 2 damage to each opponent.
+1: Add {R}{R}.
−3: Chandra, Torch of Defiance deals 4 damage to target creature.
−7: You get an emblem with "Whenever you cast a spell, this emblem deals 5 damage to any target."

Confusion in the Ranks

Whenever an artifact, creature, or enchantment enters, its controller chooses target permanent another player controls that shares a card type with it. Exchange control of those permanents.

Endless Atlas

{2}, {T}: Draw a card. Activate only if you control three or more lands with the same name.

Ingenious Artillerist

Whenever one or more artifacts you control enter, Ingenious Artillerist deals that much damage to each opponent.

Outpost Siege

As Outpost Siege enters, choose Khans or Dragons.
• Khans — At the beginning of your upkeep, exile the top card of your library. Until end of turn, you may play that card.
• Dragons — Whenever a creature you control leaves the battlefield, Outpost Siege deals 1 damage to any target.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Keldon Marauders

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Keldon Marauders enters or leaves the battlefield, it deals 1 damage to target player or planeswalker.

Fiery Emancipation

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

Torbran, Thane of Red Fell

If a red source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 2 instead.