Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Feast of Blood

Cast this spell only if you control two or more Vampires.
Destroy target creature. You gain 4 life.

Swamp

Ill-Gotten Inheritance

At the beginning of your upkeep, Ill-Gotten Inheritance deals 1 damage to each opponent and you gain 1 life.
{5}{B}, Sacrifice Ill-Gotten Inheritance: It deals 4 damage to target opponent and you gain 4 life.

Thriving Moor

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

Kalastria Nightwatch

Whenever you gain life, Kalastria Nightwatch gains flying until end of turn.

Vampire Envoy

Flying
Whenever Vampire Envoy becomes tapped, you gain 1 life.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on Bloodbond Vampire.

Oathsworn Vampire

Oathsworn Vampire enters tapped.
You may cast Oathsworn Vampire from your graveyard if you gained life this turn.

Blood Price

Look at the top four cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order. You lose 2 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.

Blood Artist

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

Moment of Craving

Target creature gets -2/-2 until end of turn. You gain 2 life.

Creeping Bloodsucker

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