Graveyard Sacrifica

{B}, Sacrifice a creature: Destroy target nonblack creature.

Castle Locthwain enters the battlefield tapped unless you control a Swamp.

{T}: Add {B}.

{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Target player sacrifices a creature. You gain life equal to that creature's toughness.

Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

You may pay 6 life and sacrifice three black creatures rather than pay this spell's mana cost.

Flying, trample

Search your library for a card, put that card into your hand, then shuffle your library.

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.)

{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.)

Enchant creature

Enchanted creature has flying and "Sacrifice a creature: This creature gets +2/+1 until end of turn."

When Fallen Ideal is put into a graveyard from the battlefield, return Fallen Ideal to its owner's hand.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

{1}{B}, Sacrifice another creature: Put two +1/+1 counters on Flesh Carver.

When Flesh Carver dies, create an X/X black Horror creature token, where X is Flesh Carver's power.

Geralf's Messenger enters the battlefield tapped.

When Geralf's Messenger enters the battlefield, target opponent loses 2 life.

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.)

Whenever a creature you control dies, each other player sacrifices a creature.

Morph {B} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Whenever another nontoken creature you control dies, draw a card.

Flying

When Kokusho, the Evening Star dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Whenever a creature you control dies, draw a card.

[+1]: Create a 2/2 black Zombie creature token.

[−4]: Each player sacrifices two creatures.

[−9]: Each opponent chooses a permanent they control of each permanent type and sacrifices the rest.

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Whenever a Human deals damage to you, destroy it.

Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying 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.)

Flying

Whenever another nontoken creature you control dies, you may exile it. If you do, create a token that's a copy of that creature, except it's 1/1 and it's a Nightmare in addition to its other types.

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token.

Rats you control have deathtouch.

Trample

Whenever a source deals damage to Phyrexian Obliterator, that source's controller sacrifices that many permanents.

Menace (This creature can't be blocked except by two or more creatures.)

When Relentless Dead dies, you may pay {B}. If you do, return it to its owner's hand.

When Relentless Dead dies, you may pay {X}. If you do, return another target Zombie creature card with converted mana cost X from your graveyard to the battlefield.

{T}: Add {B}.

{B}, {T}: Target legendary creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

When Sultai Emissary dies, manifest the top card of your library. (Put that card onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)

({T}: Add {B}.)

{T}: Add {C}.

{1}{B}, {T}: Put target creature card from your graveyard on top of your library.

Destroy target non-Merfolk creature.