Anowon, the Ruin Sage

At the beginning of your upkeep, each player sacrifices a non-Vampire creature of their choice.

Blood Hypnotist

Blood Hypnotist can't block.
Whenever you sacrifice one or more Blood tokens, target creature can't block this turn. This ability triggers only once each turn.

Bloodghast

Bloodghast can't block.
Bloodghast has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land you control enters, you may return Bloodghast from your graveyard to the battlefield.

Anje, Maid of Dishonor

Whenever Anje, Maid of Dishonor 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 artifact: Draw a card.")
{2}, Sacrifice another creature or a Blood token: Each opponent loses 2 life and you gain 2 life.

Blood Hustler

Whenever you commit a crime, put a +1/+1 counter on Blood Hustler. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
{3}{B}: Target opponent loses 1 life and you gain 1 life.

Mathas, Fiend Seeker

Menace
At the beginning of your end step, put a bounty counter on target creature an opponent controls. For as long as that creature has a bounty counter on it, it has "When this creature dies, each opponent draws a card and gains 2 life."

Bloodhusk Ritualist

Multikicker {B} (You may pay an additional {B} any number of times as you cast this spell.)
When Bloodhusk Ritualist enters, target opponent discards a card for each time it was kicked.

Bloodbond Vampire

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

Bloodflow Connoisseur

Sacrifice a creature: Put a +1/+1 counter on Bloodflow Connoisseur.

Blood Artist

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

Baron Bertram Graywater

Whenever one or more tokens you control enter, create a 1/1 black Vampire Rogue creature token with lifelink. This ability triggers only once each turn.
{1}{B}, Sacrifice another creature or artifact: Draw a card.

Bishop of Binding

When Bishop of Binding enters, exile target creature an opponent controls until Bishop of Binding leaves the battlefield.
Whenever Bishop of Binding attacks, target Vampire gets +X/+X until end of turn, where X is the power of the exiled card.

Blood Bairn

Sacrifice another creature: Blood Bairn gets +2/+2 until end of turn.

Bartolomé del Presidio

Sacrifice another creature or artifact: Put a +1/+1 counter on Bartolomé del Presidio.

Bishop of the Bloodstained

When Bishop of the Bloodstained enters, target opponent loses 1 life for each Vampire you control.

Belligerent Guest

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Belligerent Guest deals combat damage to a player, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Balustrade Spy

Flying
When Balustrade Spy enters, target player reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.