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.

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.

Lightning Prowess

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

Gang of Devils

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

Grave Exchange

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

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.)

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. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Barter in Blood

Each player sacrifices two creatures of their choice.

Reassembling Skeleton

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

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

Deathgreeter

Whenever another creature dies, you may gain 1 life.

Swamp

Soulcage Fiend

When Soulcage Fiend dies, each player loses 3 life.

Exquisite Blood

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

Raging Poltergeist

Scroll of Griselbrand

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

Bloodflow Connoisseur

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

Rush of Blood

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

Unhallowed Pact

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

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.

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.

Demonic Taskmaster

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

Demonlord of Ashmouth

Flying
When Demonlord of Ashmouth 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.)