Gelectrode

{T}: Gelectrode deals 1 damage to any target.
Whenever you cast an instant or sorcery spell, you may untap Gelectrode.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

Erebor Flamesmith

Whenever you cast an instant or sorcery spell, Erebor Flamesmith deals 1 damage to each opponent.

Electrickery

Electrickery deals 1 damage to target creature you don't control.
Overload {1}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Goblin Chainwhirler

First strike
When Goblin Chainwhirler enters, it deals 1 damage to each opponent and each creature and planeswalker they control.

Curiosity

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

Firebrand Archer

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

Spikefield Cave

Spikefield Cave enters tapped.
{T}: Add {R}.

Spikefield Hazard

Spikefield Hazard deals 1 damage to any target. If a permanent dealt damage this way would die this turn, exile it instead.

Spikefield Hazard // Spikefield Cave

Basilisk Collar

Equipped creature has deathtouch and lifelink. (Any amount of damage it deals to a creature is enough to destroy it. Damage dealt by this creature also causes you to gain that much life.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Kessig Flamebreather

Whenever you cast a noncreature spell, Kessig Flamebreather deals 1 damage to each opponent.

Electrolyze

Electrolyze deals 2 damage divided as you choose among one or two targets.
Draw a card.

Hellrider

Haste
Whenever a creature you control attacks, Hellrider deals 1 damage to the player or planeswalker it's attacking.

Tandem Lookout

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Tandem Lookout is paired with another creature, each of those creatures has "Whenever this creature deals damage to an opponent, draw a card."

Fear, Fire, Foes!

Damage can't be prevented this turn. Fear, Fire, Foes! deals X damage to target creature and 1 damage to each other creature with the same controller.

Smash to Dust

Choose one —
• Destroy target artifact.
• Destroy target creature with defender.
• Smash to Dust deals 1 damage to each creature your opponents control.

Pain Distributor

Menace
Whenever a player casts their first spell each turn, they create a Treasure token.
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, Pain Distributor deals 1 damage to that player.

Grapeshot

Grapeshot deals 1 damage to any target.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Niv-Mizzet, Parun

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

Thermo-Alchemist

Defender
{T}: Thermo-Alchemist deals 1 damage to each opponent.
Whenever you cast an instant or sorcery spell, untap Thermo-Alchemist.

End the Festivities

End the Festivities deals 1 damage to each opponent and each creature and planeswalker they control.

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.

Chandra's Incinerator

This spell costs {X} less to cast, where X is the total amount of noncombat damage dealt to your opponents this turn.
Trample
Whenever a source you control deals noncombat damage to an opponent, Chandra's Incinerator deals that much damage to target creature or planeswalker that player controls.

Gimli, Counter of Kills

Trample
Whenever a creature an opponent controls dies, Gimli, Counter of Kills deals 1 damage to that creature's controller.

Ghyrson Starn, Kelermorph

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Three Autostubs — Whenever another source you control deals exactly 1 damage to a permanent or player, Ghyrson Starn, Kelermorph deals 2 damage to that permanent or player.

Blazing Volley

Blazing Volley deals 1 damage to each creature your opponents control.

Electrostatic Field

Defender
Whenever you cast an instant or sorcery spell, Electrostatic Field deals 1 damage to each opponent.