Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap Staff of Compleation.

Unspeakable Symbol

Pay 3 life: Put a +1/+1 counter on target creature.

Blood Celebrant

{B}, Pay 1 life: Add one mana of any color.

Shivan Devastator

Flying, haste
Shivan Devastator enters with X +1/+1 counters on it.

Killing Wave

For each creature, its controller sacrifices it unless they pay X life.

Warrior's Oath

Take an extra turn after this one. At the beginning of that turn's end step, you lose the game.

Magus of the Mirror

{T}, Sacrifice Magus of the Mirror: Exchange life totals with target opponent. Activate only during your upkeep.

Vilis, Broker of Blood

Flying
{B}, Pay 2 life: Target creature gets -1/-1 until end of turn.
Whenever you lose life, draw that many cards. (Damage causes loss of life.)

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Mana Geyser

Add {R} for each tapped land your opponents control.

Rowan, Scion of War

Menace
{T}: Spells you cast this turn that are black and/or red cost {X} less to cast, where X is the amount of life you lost this turn. Activate only as a sorcery.

Bond of Agony

As an additional cost to cast this spell, pay X life.
Each other player loses X life.

Souldrinker

Pay 3 life: Put a +1/+1 counter on Souldrinker.

Cabal Pit

{T}: Add {B}. Cabal Pit deals 1 damage to you.
Threshold — {B}, {T}, Sacrifice Cabal Pit: Target creature gets -2/-2 until end of turn. Activate only if seven or more cards are in your graveyard.

Profane Command

Choose two —
• Target player loses X life.
• Return target creature card with mana value X or less from your graveyard to the battlefield.
• Target creature gets -X/-X until end of turn.
• Up to X target creatures gain fear until end of turn. (They can't be blocked except by artifact creatures and/or black creatures.)

Fire Covenant

As an additional cost to cast this spell, pay X life.
Fire Covenant deals X damage divided as you choose among any number of target creatures.

K'rrik, Son of Yawgmoth

({B/P} can be paid with either {B} or 2 life.)
Lifelink
For each {B} in a cost, you may pay 2 life rather than pay that mana.
Whenever you cast a black spell, put a +1/+1 counter on K'rrik, Son of Yawgmoth.

Their Number Is Legion

Create X tapped 2/2 black Necron Warrior artifact creature tokens, then you gain life equal to the number of artifacts you control. Exile Their Number Is Legion.
You may cast Their Number Is Legion from your graveyard.

Wall of Blood

Defender (This creature can't attack.)
Pay 1 life: Wall of Blood gets +1/+1 until end of turn.

Barbarian Ring

{T}: Add {R}. Barbarian Ring deals 1 damage to you.
Threshold — {R}, {T}, Sacrifice Barbarian Ring: It deals 2 damage to any target. Activate only if seven or more cards are in your graveyard.

Doom Whisperer

Flying, trample
Pay 2 life: Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)