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.

Strefan, Maurer Progenitor

Flying
At the beginning of your end step, create a Blood token for each player who lost life this turn.
Whenever Strefan attacks, you may sacrifice two Blood tokens. If you do, you may put a Vampire card from your hand onto the battlefield tapped and attacking. It gains indestructible until end of turn.

Blood for the Blood God!

This spell costs {1} less to cast for each creature that died this turn.
Discard your hand, then draw eight cards. Blood for the Blood God! deals 8 damage to each opponent. Exile Blood for the Blood God!

Blood Crypt

({T}: Add {B} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on this enchantment. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if this enchantment has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

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 this creature deals combat damage to a player, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Bloodcrazed Socialite

Menace
When this creature enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Whenever this creature attacks, you may sacrifice a Blood token. If you do, it gets +2/+2 until end of turn.

Arterial Alchemy

When this enchantment enters, create a Blood token for each opponent you have. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
Blood tokens you control are Equipment in addition to their other types and have "Equipped creature gets +2/+0" and equip {2}.

Bloodfell Caves

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

Blood Fountain

When this artifact enters, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")
{3}{B}, {T}, Sacrifice this artifact: Return up to two target creature cards from your graveyard to your hand.