Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Rend Flesh

Phyrexian Ghoul

Sacrifice a creature: Phyrexian Ghoul gets +2/+2 until end of turn.

Will-o'-the-Wisp

Flying (This creature can't be blocked except by creatures with flying or reach.)
{B}: Regenerate Will-o'-the-Wisp. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Havoc Demon

Flying
When Havoc Demon dies, all creatures get -5/-5 until end of turn.

Nantuko Husk

Sacrifice a creature: Nantuko Husk gets +2/+2 until end of turn.

Bile Urchin

Sacrifice Bile Urchin: Target player loses 1 life.

Culling the Weak

As an additional cost to cast this spell, sacrifice a creature.
Add {B}{B}{B}{B}.

Grave Pact

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

Swamp

One with Nothing

Plagued Rusalka

{B}, Sacrifice a creature: Target creature gets -1/-1 until end of turn.

Festering Goblin

When Festering Goblin dies, target creature gets -1/-1 until end of turn.

Diabolic Tutor

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

Mortal Combat

At the beginning of your upkeep, if twenty or more creature cards are in your graveyard, you win the game.