Bloodflow Connoisseur

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

Blood Artist

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

Human Frailty

Harvester of Souls

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another nontoken creature dies, you may draw a card.

Demonlord of Ashmouth

Flying
When this creature enters, exile it unless you sacrifice another creature.
Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Butcher Ghoul

Undying (When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Undead Executioner

When this creature dies, you may have target creature get -2/-2 until end of turn.

Soulcage Fiend

When this creature dies, each player loses 3 life.

Bone Splinters

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

Demonic Taskmaster

Flying
At the beginning of your upkeep, sacrifice a creature other than this creature.