Havengul Vampire

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

Mountain

Reassembling Skeleton

{1}{B}: Return Reassembling Skeleton from your graveyard to the battlefield tapped.

Rush of Blood

Target creature gets +X/+0 until end of turn, where X is its power.

Gang of Devils

When Gang of Devils dies, it deals 3 damage divided as you choose among one, two, or three targets.

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.

Driver of the Dead

When Driver of the Dead dies, return target creature card with mana value 2 or less from your graveyard to the battlefield.

Raging Poltergeist

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Soulcage Fiend

When Soulcage Fiend dies, each player loses 3 life.

Harvester of Souls

Deathtouch
Whenever another nontoken creature dies, you may draw a card.

Barter in Blood

Grave Exchange

Return target creature card from your graveyard to your hand. Target player sacrifices a creature.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Bone Splinters

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

Mortivore

Mortivore's power and toughness are each equal to the number of creature cards in all graveyards.
{B}: Regenerate Mortivore.

Evernight Shade

{B}: Evernight Shade gets +1/+1 until end of turn.
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.)

Unhallowed Pact

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Demonlord of Ashmouth

Flying
When Demonlord of Ashmouth enters the battlefield, 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.)

Swamp

Bloodflow Connoisseur

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

Scroll of Griselbrand

{1}, Sacrifice Scroll of Griselbrand: Target opponent discards a card. If you control a Demon, that player loses 3 life.

Demonic Taskmaster

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

Lightning Prowess

Enchant creature
Enchanted creature has haste and "{T}: This creature deals 1 damage to any target."

Heirs of Stromkirk

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever Heirs of Stromkirk deals combat damage to a player, put a +1/+1 counter on it.