Immolating Gyre

Immolating Gyre deals X damage to each creature and planeswalker you don't control, where X is the number of instant and sorcery cards in your graveyard.

Assassin's Strike

Destroy target creature. Its controller discards a card.

Bake into a Pie

Food

Destroy target creature. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Barter in Blood

Each player sacrifices two creatures of their choice.

Black Cat

When this creature dies, target opponent discards a card at random.

Black Market

Whenever a creature dies, put a charge counter on this enchantment.
At the beginning of your first main phase, add {B} for each charge counter on this enchantment.

Blighted Bat

Flying
{1}: This creature gains haste until end of turn.

A-Blood Artist

Blood Artist

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

Blood Divination

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

Blood Host

{1}{B}, Sacrifice another creature: Put a +1/+1 counter on this creature and you gain 2 life.

Bloodbond Vampire

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

Lightning Phoenix

Flying, haste
This creature can't block.
At the beginning of your end step, if an opponent was dealt 3 or more damage this turn, you may pay {R}. If you do, return this card from your graveyard to the battlefield.

Bloodhunter Bat

Flying
When this creature enters, target player loses 2 life and you gain 2 life.

Festering Newt

Bogbrew Witch

Bubbling Cauldron

{2}, {T}: Search your library for a card named Festering Newt or Bubbling Cauldron, put it onto the battlefield tapped, then shuffle.

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Bone Splinters

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

Jumpstart