Plague Mare

Plague Mare can't be blocked by white creatures.
When Plague Mare enters the battlefield, creatures your opponents control get -1/-1 until end of turn.

Audacious Thief

Whenever Audacious Thief attacks, you draw a card and you lose 1 life.

Defile

Target creature gets -1/-1 until end of turn for each Swamp you control.

Dusk Legion Zealot

When Dusk Legion Zealot enters the battlefield, you draw a card and you lose 1 life.

Kaervek, the Spiteful

Bad Deal

You draw two cards and each opponent discards two cards. Each player loses 2 life.

Clockwork Servant

Adamant — When Clockwork Servant enters the battlefield, if at least three mana of the same color was spent to cast it, draw a card.

Festergloom

Nonblack creatures get -1/-1 until end of turn.

Blood Divination

As an additional cost to cast this spell, sacrifice a creature.
Draw three cards.

Make Obsolete

Creatures your opponents control get -1/-1 until end of turn.

Umezawa's Charm

Choose one —
• Target creature gets +2/+2 until end of turn.
• Target creature gets -1/-1 until end of turn.
• You gain 2 life.

Armix, Filigree Thrasher

Whenever Armix, Filigree Thrasher attacks, you may discard a card. When you do, target creature defending player controls gets -X/-X until end of turn, where X is the number of artifacts you control plus the number of artifact cards in your graveyard.
Partner (You can have two commanders if both have partner.)

Ancestral Vengeance

Enchant creature
When Ancestral Vengeance enters the battlefield, put a +1/+1 counter on target creature you control.
Enchanted creature gets -1/-1.

Succumb to Temptation

Weed-Pruner Poplar

At the beginning of your upkeep, target creature other than Weed-Pruner Poplar gets -1/-1 until end of turn.

Annihilate

Destroy target nonblack creature. It can't be regenerated.
Draw a card.

Necropolis Fiend

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying
{X}, {T}, Exile X cards from your graveyard: Target creature gets -X/-X until end of turn.

Briarblade Adept

Whenever Briarblade Adept attacks, target creature an opponent controls gets -1/-1 until end of turn.
Encore {3}{B} ({3}{B}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Ambition's Cost

You draw three cards and you lose 3 life.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Filigree Familiar

When Filigree Familiar enters the battlefield, you gain 2 life.
When Filigree Familiar dies, draw a card.

Massacre Girl

Menace
When Massacre Girl enters the battlefield, each other creature gets -1/-1 until end of turn. Whenever a creature dies this turn, each creature other than Massacre Girl gets -1/-1 until end of turn.

Painful Lesson

Target player draws two cards and loses 2 life.

Nausea

All creatures get -1/-1 until end of turn.

Night of Souls' Betrayal

Cower in Fear

Malakir Soothsayer

Cohort — {T}, Tap an untapped Ally you control: You draw a card and you lose 1 life.

Suffocating Fumes

Creatures your opponents control get -1/-1 until end of turn.
Cycling {2} ({2}, Discard this card: Draw a card.)

Ifnir Deadlands

{T}: Add {C}.
{T}, Pay 1 life: Add {B}.
{2}{B}{B}, {T}, Sacrifice a Desert: Put two -1/-1 counters on target creature an opponent controls. Activate only as a sorcery.