Have

Blood Seeker

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

Alchemist's Gift

Target creature gets +1/+1 and gains your choice of deathtouch or lifelink until end of turn. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it. Damage dealt by a creature with lifelink also causes its controller to gain that much life.)

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on this creature.

Vampire Lacerator

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

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Bloodrage Vampire

Bloodthirst 1 (If an opponent was dealt damage this turn, this creature enters with a +1/+1 counter on it.)

Tenured Inkcaster

When this creature enters, put a +1/+1 counter on target creature.
Whenever a creature you control with a +1/+1 counter on it attacks, each opponent loses 1 life and you gain 1 life.

Deathless Ancient

Flying
Tap three untapped Vampires you control: Return this card from your graveyard to your hand.

Stromkirk Patrol

Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.

Blood Glutton

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Sadistic Skymarcher

As an additional cost to cast this spell, reveal a Vampire card from your hand or pay {1}.
Flying, lifelink

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Sign in Blood

Target player draws two cards and loses 2 life.

Child of Night

Traitorous Instinct

Gain control of target creature until end of turn. Untap that creature. Until end of turn, it gets +2/+0 and gains haste.

Traitorous Blood

Gain control of target creature until end of turn. Untap it. It gains trample and haste until end of turn.

Dark Ritual

Falkenrath Exterminator

Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.
{2}{R}: This creature deals damage to target creature equal to the number of +1/+1 counters on this creature.

Westgate Regent

Flying
Ward—Discard a card. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player discards a card.)
Whenever this creature deals combat damage to a player, put that many +1/+1 counters on it.

Mark of the Vampire

Enchant creature
Enchanted creature gets +2/+2 and has lifelink.

Vampire Neonate

{2}, {T}: Each opponent loses 1 life and you gain 1 life.

Vampire Spawn

When this creature enters, each opponent loses 2 life and you gain 2 life.

Vampiric Fury

Vampire creatures you control get +2/+0 and gain first strike until end of turn. (They deal combat damage before creatures without first strike.)

Bold Impaler

{2}{R}: This creature gets +2/+0 until end of turn.

Swamp

Act of Treason

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. (It can attack and {T} this turn.)

Claim the Firstborn

Gain control of target creature with mana value 3 or less until end of turn. Untap that creature. It gains haste until end of turn.

Bloodthrone Vampire

Sacrifice a creature: This creature gets +2/+2 until end of turn.

Mountain

Vampire Outcasts

Bloodthirst 2 (If an opponent was dealt damage this turn, this creature enters with two +1/+1 counters on it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Terramorphic Expanse

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Savage Gorger

Flying
At the beginning of your end step, if an opponent lost life this turn, put a +1/+1 counter on this creature. (Damage causes loss of life.)

Havengul Vampire

Whenever this creature deals combat damage to a player, put a +1/+1 counter on it.
Whenever another creature dies, put a +1/+1 counter on this creature.

Bloodbond Vampire

Whenever you gain life, put a +1/+1 counter on this creature.

Skymarch Bloodletter

Flying
When this creature enters, target opponent loses 1 life and you gain 1 life.

Bloodfell Caves

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {R}.

Bone Splinters

As an additional cost to cast this spell, sacrifice a creature.
Destroy target creature.

Evolving Wilds

Shadow Alley Denizen

Whenever another black creature you control enters, target creature gains intimidate until end of turn. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)