Have

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.

Termination Facilitator

{T}: Put a bounty counter on target creature or planeswalker. Activate only as a sorcery.
Whenever a creature or planeswalker an opponent controls with a bounty counter on it is dealt damage, destroy it.

Lurking Deadeye

Flash
When this creature enters, destroy target creature that was dealt damage this turn.

Conductor of Cacophony

This creature enters with two +1/+1 counters on it.
{B}, Remove a +1/+1 counter from this creature: It deals 1 damage to each other creature and each player.

Feast on the Fallen

At the beginning of each upkeep, if an opponent lost life last turn, put a +1/+1 counter on target creature you control.

Cruel Sadist

{B}, {T}, Pay 1 life: Put a +1/+1 counter on this creature.
{2}{B}, {T}, Remove X +1/+1 counters from this creature: It deals X damage to target creature.

Talon of Pain

Whenever a source you control other than this artifact deals damage to an opponent, put a charge counter on this artifact.
{X}, {T}, Remove X charge counters from this artifact: It deals X damage to any target.

Swamp

Hooded Assassin

When this creature enters, choose one —
• Put a +1/+1 counter on this creature.
• Destroy target creature that was dealt damage this turn.

Festering Evil

At the beginning of your upkeep, this enchantment deals 1 damage to each creature and each player.
{B}{B}, Sacrifice this enchantment: It deals 3 damage to each creature and each player.

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Dread Slaver

Whenever a creature dealt damage by this creature this turn dies, return it to the battlefield under your control. That creature is a black Zombie in addition to its other colors and types.

Tormented Soul

This creature can't block and can't be blocked.

Nested Ghoul

Whenever a source deals damage to this creature, create a 2/2 black Phyrexian Zombie creature token.

Creeping Bloodsucker

At the beginning of your upkeep, this creature deals 1 damage to each opponent. You gain life equal to the damage dealt this way.

Mire Blight

Enchant creature
When enchanted creature is dealt damage, destroy it.

Dread Presence

Whenever a Swamp you control enters, choose one —
• You draw a card and you lose 1 life.
• This creature deals 2 damage to any target and you gain 2 life.

Thriving Moor

This land enters tapped. As it enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Ob Nixilis, the Hate-Twisted

Whenever an opponent draws a card, Ob Nixilis deals 1 damage to that player.
−2: Destroy target creature. Its controller draws two cards.

Ossuary Rats

When this creature enters, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

Ob Nixilis's Cruelty

Target creature gets -5/-5 until end of turn. If that creature would die this turn, exile it instead.

Wicked Guardian

When this creature enters, you may have it deal 2 damage to another creature you control. If you do, draw a card.