Bone Splinters

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

Demon's Due

Scry 2, then draw two cards. You lose 2 life.

Phyrexian Rager

When this creature enters, you draw a card and you lose 1 life.

Marauding Blight-Priest

Whenever you gain life, each opponent loses 1 life.

Festering Mummy

When this creature dies, you may put a -1/-1 counter on target creature.

Village Rites

As an additional cost to cast this spell, sacrifice a creature.
Draw two cards.

Dune Beetle

Swamp

Sicken

Enchant creature
Enchanted creature gets -1/-1.
Cycling {2} ({2}, Discard this card: Draw a card.)

Carrier Thrall

When this creature dies, create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this token: Add {C}."

Snow-Covered Swamp

Thrill-Kill Assassin

Deathtouch
Unleash (You may have this creature enter with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)

Painful Lesson

Target player draws two cards and loses 2 life.

Trespasser's Curse

Enchant player
Whenever a creature enchanted player controls enters, that player loses 1 life and you gain 1 life.

Mind Rot

Ambition's Cost

You draw three cards and you lose 3 life.

Splendid Agony

Distribute two -1/-1 counters among one or two target creatures.

Gray Merchant of Asphodel

When this creature enters, each opponent loses X life, where X is your devotion to black. You gain life equal to the life lost this way. (Each {B} in the mana costs of permanents you control counts toward your devotion to black.)