Massacre Wurm

When this creature enters, creatures your opponents control get -2/-2 until end of turn.
Whenever a creature an opponent controls dies, that player loses 2 life.

Ayara, First of Locthwain

Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life.
{T}, Sacrifice another black creature: Draw a card.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)

Gifted Aetherborn

Duress

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Knight of the Ebon Legion

{2}{B}: This creature gets +3/+3 and gains deathtouch until end of turn.
At the beginning of your end step, if a player lost 4 or more life this turn, put a +1/+1 counter on this creature. (Damage causes loss of life.)

Evolved Sleeper

{B}: This creature becomes a Human Cleric with base power and toughness 2/2.
{1}{B}: If this creature is a Cleric, put a deathtouch counter on it and it becomes a Phyrexian Human Cleric with base power and toughness 3/3.
{1}{B}{B}: If this creature is a Phyrexian, put a +1/+1 counter on it, then you draw a card and you lose 1 life.

Swamp

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Dread Shade

{B}: This creature gets +1/+1 until end of turn.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Fatal Push

Destroy target creature if it has mana value 2 or less.
Revolt — Destroy that creature if it has mana value 4 or less instead if a permanent left the battlefield under your control this turn.

Invoke Despair

Target opponent sacrifices a creature of their choice. If they can't, they lose 2 life and you draw a card. Then repeat this process for an enchantment and a planeswalker.

Phyrexian Obliterator

Trample
Whenever a source deals damage to this creature, that source's controller sacrifices that many permanents of their choice.

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When this creature dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Profane Insight

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Foulmire Knight

Foulmire Knight // Profane Insight

Tymaret, Chosen from Death

Tymaret's toughness is equal to your devotion to black. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)
{1}{B}: Exile up to two target cards from graveyards. You gain 1 life for each creature card exiled this way.

Graveyard Glutton

Ward—Discard a card.
Whenever this creature enters or attacks, exile up to two target cards from graveyards. For each creature card exiled this way, each opponent loses 1 life and you gain 1 life.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Graveyard Trespasser

Ward—Discard a card.
Whenever this creature enters or attacks, exile up to one target card from a graveyard. If a creature card was exiled this way, each opponent loses 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)