Blasphemous Act

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

Rush of Vitality

Target creature gets +1/+0 and gains lifelink and indestructible until end of turn. (Damage dealt by that creature also causes its controller to gain that much life, and it can't be destroyed by damage or effects that say "destroy.")

Thrashing Wumpus

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

End the Festivities

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

Pyrohemia

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

Blazing Volley

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

Dry Spell

Dry Spell deals 1 damage to each creature and each player.

Soul's Fire

Target creature you control deals damage equal to its power to any target.

Kazarov, Sengir Pureblood

Flying
Whenever a creature an opponent controls is dealt damage, put a +1/+1 counter on Kazarov.
{3}{R}: Kazarov deals 2 damage to target creature.

Cosmotronic Wave

Cosmotronic Wave deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Plague Spitter

At the beginning of your upkeep, this creature deals 1 damage to each creature and each player.
When this creature dies, it deals 1 damage to each creature and each player.

Kediss, Emberclaw Familiar

Whenever a commander you control deals combat damage to an opponent, it deals that much damage to each other opponent.
Partner (You can have two commanders if both have partner.)

Barrage of Boulders

Barrage of Boulders deals 1 damage to each creature you don't control.
Ferocious — If you control a creature with power 4 or greater, creatures can't block this turn.

Harvester of Souls

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another nontoken creature dies, you may draw a card.

Bolt Bend

This spell costs {3} less to cast if you control a creature with power 4 or greater.
Change the target of target spell or ability with a single target.

Inflame

Inflame deals 2 damage to each creature dealt damage this turn.

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.")

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.

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.

Akroan Horse

Defender
When this creature enters, an opponent gains control of it.
At the beginning of your upkeep, each opponent creates a 1/1 white Soldier creature token.

Deathbringer Thoctar

Whenever another creature dies, you may put a +1/+1 counter on this creature.
Remove a +1/+1 counter from this creature: It deals 1 damage to any target.

Shake the Foundations

Shake the Foundations deals 1 damage to each creature without flying.
Draw a card.

Caltrops

Whenever a creature attacks, this artifact deals 1 damage to it.

Burnished Hart

{3}, Sacrifice this creature: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Rain of Embers

Rain of Embers deals 1 damage to each creature and each player.

Fire Ants

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

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.)

Crypt Rats

{X}: This creature deals X damage to each creature and each player. Spend only black mana on X.

Brash Taunter

Indestructible
Whenever this creature is dealt damage, it deals that much damage to target opponent.
{2}{R}, {T}: This creature fights another target creature.

Mahadi, Emporium Master

At the beginning of your end step, create a Treasure token for each creature that died this turn. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

You Are Already Dead

Destroy target creature that was dealt damage this turn.
Draw a card.

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

Pestilence

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

Silverclad Ferocidons

Enrage — Whenever this creature is dealt damage, each opponent sacrifices a permanent of their choice.

Gadrak, the Crown-Scourge

Flying
Gadrak can't attack unless you control four or more artifacts.
At the beginning of your end step, create a Treasure token for each nontoken creature that died this turn. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Judith, Carnage Connoisseur

Whenever you cast an instant or sorcery spell, choose one —
• That spell gains deathtouch and lifelink.
• Create a 2/2 red Imp creature token with "When this token dies, it deals 2 damage to each opponent."