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.

Sparkmage Apprentice

When Sparkmage Apprentice enters the battlefield, it deals 1 damage to any target.

Zo-Zu the Punisher

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

Prodigal Pyromancer

{T}: Prodigal Pyromancer deals 1 damage to any target.

Spark Mage

Whenever Spark Mage deals combat damage to a player, you may have Spark Mage deal 1 damage to target creature that player controls.

Embermage Goblin

When Embermage Goblin enters the battlefield, you may search your library for a card named Embermage Goblin, reveal it, put it into your hand, then shuffle.
{T}: Embermage Goblin deals 1 damage to any target.

Falkenrath Marauders

Flying, haste
Whenever Falkenrath Marauders deals combat damage to a player, put two +1/+1 counters on it.

Hammerfist Giant

{T}: Hammerfist Giant deals 4 damage to each creature without flying and each player.

Shepherd of Rot

{T}: Each player loses 1 life for each Zombie on the battlefield.

Reckless Embermage

{1}{R}: Reckless Embermage deals 1 damage to any target and 1 damage to itself.

Blood Cultist

{T}: Blood Cultist deals 1 damage to target creature.
Whenever a creature dealt damage by Blood Cultist this turn dies, put a +1/+1 counter on Blood Cultist.

Infected Vermin

{2}{B}: Infected Vermin deals 1 damage to each creature and each player.
Threshold — {3}{B}: Infected Vermin deals 3 damage to each creature and each player. Activate only if seven or more cards are in your graveyard.

Goblin Chainwhirler

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

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Goblin Cratermaker

{1}, Sacrifice Goblin Cratermaker: Choose one —
• Goblin Cratermaker deals 2 damage to target creature.
• Destroy target colorless nonland permanent.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Oona's Blackguard

Flying
Each other Rogue creature you control enters the battlefield with an additional +1/+1 counter on it.
Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, that player discards a card.

Lyzolda, the Blood Witch

{2}, Sacrifice a creature: Lyzolda, the Blood Witch deals 2 damage to any target if the sacrificed creature was red. Draw a card if the sacrificed creature was black.

Fireslinger

{T}: Fireslinger deals 1 damage to any target and 1 damage to you.

Vampire Envoy

Flying
Whenever Vampire Envoy becomes tapped, you gain 1 life.

Rakdos Firewheeler

When Rakdos Firewheeler enters the battlefield, it deals 2 damage to target opponent and 2 damage to up to one target creature or planeswalker.

Grim Lavamancer

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

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

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.

Sandstone Warrior

First strike (This creature deals combat damage before creatures without first strike.)
{R}: Sandstone Warrior gets +1/+0 until end of turn.

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Pontiff of Blight

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)
Other creatures you control have extort. (If a creature has multiple instances of extort, each triggers separately.)

Skirsdag Supplicant

{B}, {T}, Discard a card: Each player loses 2 life.

Goblin Sharpshooter

Goblin Sharpshooter doesn't untap during your untap step.
Whenever a creature dies, untap Goblin Sharpshooter.
{T}: Goblin Sharpshooter deals 1 damage to any target.

Heartfire Immolator

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{R}, Sacrifice Heartfire Immolator: It deals damage equal to its power to target creature or planeswalker.

Priest of Gix

When Priest of Gix enters the battlefield, add {B}{B}{B}.

Burning Earth

Whenever a player taps a nonbasic land for mana, Burning Earth deals 1 damage to that player.

Priest of Urabrask

When Priest of Urabrask enters the battlefield, add {R}{R}{R}.

Goblin Fireslinger

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

Fire Ants

{T}: Fire Ants deals 1 damage to each other creature without flying.

Cuombajj Witches

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.

Onyx Mage

{1}{B}: Target creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Rustrazor Butcher

First strike
Wither (This deals damage to creatures in the form of -1/-1 counters.)

Wojek Embermage

Radiance — {T}: Wojek Embermage deals 1 damage to target creature and each other creature that shares a color with it.

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.

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters the battlefield under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Orzhov Racketeers

Whenever Orzhov Racketeers deals combat damage to a player, that player discards a card.
Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

Hatchet Bully

{2}{R}, {T}, Put a -1/-1 counter on a creature you control: Hatchet Bully deals 2 damage to any target.

Viashino Fangtail

{T}: Viashino Fangtail deals 1 damage to any target.

Dagger Caster

When Dagger Caster enters the battlefield, it deals 1 damage to each opponent and 1 damage to each creature your opponents control.

Pulse Tracker

Whenever Pulse Tracker attacks, each opponent loses 1 life.

Inescapable Brute

Wither (This deals damage to creatures in the form of -1/-1 counters.)
Inescapable Brute must be blocked if able.

Thrashing Wumpus

{B}: Thrashing Wumpus deals 1 damage to each creature and each player.

Fervent Paincaster

{T}: Fervent Paincaster deals 1 damage to target player or planeswalker.
{T}, Exert Fervent Paincaster: It deals 1 damage to target creature. (An exerted creature won't untap during your next untap step.)

Cabal Executioner

Whenever Cabal Executioner deals combat damage to a player, that player sacrifices a creature.
Morph {3}{B}{B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Gangrenous Zombies

{T}, Sacrifice Gangrenous Zombies: Gangrenous Zombies deals 1 damage to each creature and each player. If you control a snow Swamp, Gangrenous Zombies deals 2 damage to each creature and each player instead.

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.

Ambush Party

Hellhole Flailer

Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
{2}{B}{R}, Sacrifice Hellhole Flailer: Hellhole Flailer deals damage equal to its power to target player or planeswalker.

Jeska, Warrior Adept

First strike, haste
{T}: Jeska, Warrior Adept deals 1 damage to any target.

Spireside Infiltrator

Whenever Spireside Infiltrator becomes tapped, it deals 1 damage to each opponent.

Mage il-Vec

{T}, Discard a card at random: Mage il-Vec deals 1 damage to any target.

Twilight Prophet

Flying
Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your upkeep, if you have the city's blessing, reveal the top card of your library and put it into your hand. Each opponent loses X life and you gain X life, where X is that card's mana value.