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.)

Mortify

Sanguine Bond

Whenever you gain life, target opponent loses that much life.

Vito, Thorn of the Dusk Rose

Whenever you gain life, target opponent loses that much life.
{3}{B}{B}: Creatures you control gain lifelink until end of turn.

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Debt to the Deathless

Each opponent loses two times X life. You gain life equal to the life lost this way.

Mister Negative

Vigilance, lifelink
Darkforce Inversion — When Mister Negative enters, you may exchange life totals with target opponent. If you lose life this way, draw that many cards.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Elenda's Hierophant

Flying
Whenever you gain life, put a +1/+1 counter on this creature.
When this creature dies, create X 1/1 white Vampire creature tokens with lifelink, where X is its power.

Orzhov Signet

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Astarion's Thirst

Exile target creature. Put X +1/+1 counters on a commander creature you control, where X is the power of the creature exiled this way.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Markov Purifier

Lifelink
At the beginning of your end step, if you gained life this turn, you may pay {2}. If you do, draw a card.

Blood Artist

Whenever this creature or another creature dies, target player loses 1 life and you gain 1 life.

Indulging Patrician

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
At the beginning of your end step, if you gained 3 or more life this turn, each opponent loses 3 life.

Cliffhaven Vampire

Flying
Whenever you gain life, each opponent loses 1 life.

Defiant Bloodlord

Flying
Whenever you gain life, target opponent loses that much life.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Astarion, the Decadent

Deathtouch, lifelink
At the beginning of your end step, choose one —
• Feed — Target opponent loses life equal to the amount of life they lost this turn.
• Friends — You gain life equal to the amount of life you gained this turn.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

Arcane Signet

Kambal, Consul of Allocation

Whenever an opponent casts a noncreature spell, that player loses 2 life and you gain 2 life.

Sol Ring

Revenge

Double your life total. Target opponent loses half their life, rounded up.

Revival

Return target creature card with mana value 3 or less from your graveyard to the battlefield.