Rodolf Duskbringer

Flying, deathtouch, lifelink
Whenever you gain life, Rodolf Duskbringer gains indestructible until end of turn.
At the beginning of your end step, you may pay {1}{W/B}. When you do, return target creature card with mana value X or less from your graveyard to the battlefield, where X is the amount of life you gained this turn.

Elenda, Saint of Dusk

Lifelink, hexproof from instants
As long as your life total is greater than your starting life total, Elenda gets +1/+1 and has menace. Elenda gets an additional +5/+5 as long as your life total is at least 10 greater than your starting life total.

Blood Artist

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

Charismatic Conqueror

Vigilance
Whenever an artifact or creature an opponent controls enters untapped, they may tap that permanent. If they don't, you create a 1/1 white Vampire creature token with lifelink.

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.

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.

Bloodthirsty Conqueror

Flying, deathtouch
Whenever an opponent loses life, you gain that much life. (Damage causes loss of life.)

Vona, Butcher of Magan

Vigilance, lifelink
{T}, Pay 7 life: Destroy target nonland permanent. Activate only during your turn.

Mavren Fein, Dusk Apostle

Whenever one or more nontoken Vampires you control attack, create a 1/1 white Vampire creature token with lifelink.

Blood Seeker

Whenever a creature an opponent controls enters, you may have that player lose 1 life.