Glass-Cast Heart

Whenever one or more Vampires you control attack, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{B}, {T}, Pay 1 life: Create a 1/1 white and black Vampire creature token with lifelink.
{B}{B}, {T}, Sacrifice this artifact and thirteen Blood tokens: Each opponent loses 13 life and you gain 13 life.

Anje, Maid of Dishonor

Whenever Anje and/or one or more other Vampires you control enter, create a Blood token. This ability triggers only once each turn. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{2}, Sacrifice another creature or a Blood token: Each opponent loses 2 life and you gain 2 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.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Kambal, Consul of Allocation

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

Bloodsoaked Reveler

At the beginning of your end step, if you gained life this turn, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{4}{B}: Each opponent loses 2 life and you gain 2 life.

Restless Bloodseeker

At the beginning of your end step, if you gained life this turn, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Sacrifice two Blood tokens: Transform this creature. Activate only as a sorcery.

Restless Bloodseeker // Bloodsoaked Reveler

Licia, Sanguine Tribune

This spell costs {1} less to cast for each 1 life you gained this turn.
First strike, lifelink
Pay 5 life: Put three +1/+1 counters on Licia. Activate only during your turn and only once each turn.

Creeping Bloodsucker

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

Parasitic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, its controller loses 2 life and you gain 2 life.

Cliffhaven Vampire

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

Pristine Talisman

Malakir Bloodwitch

Flying, protection from white
When this creature enters, each opponent loses life equal to the number of Vampires you control. You gain life equal to the life lost this way.

Sun Droplet

Whenever you're dealt damage, put that many charge counters on this artifact.
At the beginning of each upkeep, you may remove a charge counter from this artifact. If you do, you gain 1 life.

Cruel Celebrant

Whenever this creature or another creature or planeswalker you control dies, each opponent loses 1 life and you gain 1 life.