Have

Blood Seeker

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

Vampire Lacerator

At the beginning of your upkeep, you lose 1 life unless an opponent has 10 or less life.

Disfigure

Target creature gets -2/-2 until end of turn.

Nightwing Shade

Flying
{1}{B}: This creature gets +1/+1 until end of turn.

Soul Feast

Target player loses 4 life and you gain 4 life.

Urge to Feed

Target creature gets -3/-3 until end of turn. You may tap any number of untapped Vampire creatures you control. If you do, put a +1/+1 counter on each of those Vampires.

Memory Sluice

Target player mills four cards.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Liliana's Specter

Flying
When this creature enters, each opponent discards a card.

Accursed Spirit

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Herald of Torment

Bestow {3}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
Flying
At the beginning of your upkeep, you lose 1 life.
Enchanted creature gets +3/+3 and has flying.

Liliana's Caress

Whenever an opponent discards a card, that player loses 2 life.

Pharika's Chosen

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Corrupt

Corrupt deals damage to any target equal to the number of Swamps you control. You gain life equal to the damage dealt this way.

Swamp

Demigod of Revenge

When you cast this spell, return all cards named Demigod of Revenge from your graveyard to the battlefield.
Flying, haste

Getting

Doom Blade

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Child of Night

Wanderbrine Rootcutters

This creature can't be blocked by green creatures.

Three Tragedies

Feast of Blood

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

Sengir Vampire

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever a creature dealt damage by this creature this turn dies, put a +1/+1 counter on this creature.

Tendrils of Despair

As an additional cost to cast this spell, sacrifice a creature.
Target opponent discards two cards.

Caustic Tar

Enchant land
Enchanted land has "{T}: Target player loses 3 life."

Ruthless Cullblade

This creature gets +2/+1 as long as an opponent has 10 or less life.

Pulse Tracker

Whenever this creature attacks, each opponent loses 1 life.

Cast into Darkness

Enchant creature
Enchanted creature gets -2/-0 and can't block.

Unholy Strength

Enchant creature
Enchanted creature gets +2/+1.

Returned Reveler

When this creature dies, each player mills three cards.

Death Cultist

Sacrifice this creature: Target player loses 1 life and you gain 1 life.

Blood Tithe

Each opponent loses 3 life. You gain life equal to the life lost this way.