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.

Shower of Sparks

Shower of Sparks deals 1 damage to target creature and 1 damage to target player or planeswalker.

End the Festivities

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

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."

Steam Clean

Return target nonland permanent to its owner's hand. (Then exile this card. You may cast the creature later from exile.)

Scalding Viper

Whenever an opponent casts a spell with mana value 3 or less, Scalding Viper deals 1 damage to that player.

Scalding Viper // Steam Clean

Thermo-Alchemist

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

Razorfin Hunter

{T}: Razorfin Hunter deals 1 damage to any target.

Gorgon's Head

Equipped creature has deathtouch.
Equip {2}

Witty Roastmaster

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

Dramatic Reversal

Untap all nonland permanents you control.

Ophidian Eye

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Whenever enchanted creature deals damage to an opponent, you may draw a card.

Scouring Sands

Scouring Sands deals 1 damage to each creature your opponents control. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Kessig Flamebreather

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

Forked Bolt

Forked Bolt deals 2 damage divided as you choose among one or two targets.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Firebrand Archer

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

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.

Lobber Crew

Defender
{T}: Lobber Crew deals 1 damage to each opponent.
Whenever you cast a multicolored spell, untap Lobber Crew.

Tectonic Hazard

Tectonic Hazard deals 1 damage to each opponent and each creature they control.

Flick a Coin

Flick a Coin deals 1 damage to any target. You create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Draw a card.

Unruly Catapult

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

Hissing Iguanar

Whenever another creature dies, you may have Hissing Iguanar deal 1 damage to target player or planeswalker.

Spiteful Prankster

During your turn, Spiteful Prankster has first strike.
Whenever another creature dies, Spiteful Prankster deals 1 damage to target player or planeswalker.

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.)

Eroded Canyon

Eroded Canyon enters tapped.
When Eroded Canyon enters, it deals 1 damage to target opponent.
{T}: Add {U} or {R}.

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.")

Curiosity

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

Blisterspit Gremlin

{1}, {T}: Blisterspit Gremlin deals 1 damage to each opponent.
Whenever you cast a noncreature spell, untap Blisterspit Gremlin.

Goblin Chainwhirler

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

Cinder Pyromancer

{T}: Cinder Pyromancer deals 1 damage to target player or planeswalker.
Whenever you cast a red spell, you may untap Cinder Pyromancer.

Goblin Fireslinger

{T}: Goblin Fireslinger deals 1 damage to target player or planeswalker.

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.)

Mischievous Chimera

Flying
Whenever you cast your first spell during each opponent's turn, Mischievous Chimera deals 1 damage to each opponent. Scry 1.

Flame Fusillade

Until end of turn, permanents you control gain "{T}: This permanent deals 1 damage to any target."

Gelectrode

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

Impact Tremors

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

Tunneling Geopede

Landfall — Whenever a land you control enters, Tunneling Geopede deals 1 damage to each opponent.

Needle Drop

Needle Drop deals 1 damage to any target that was dealt damage this turn.
Draw a card.

Boiling Earth

Boiling Earth deals 1 damage to each creature your opponents control.
Awaken 4—{6}{R} (If you cast this spell for {6}{R}, also put four +1/+1 counters on target land you control and it becomes a 0/0 Elemental creature with haste. It's still a land.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Spear Spewer

Defender
{T}: Spear Spewer deals 1 damage to each player.

Electrostatic Field

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

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.

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.)