Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice this enchantment.
{B}: This enchantment deals 1 damage to each creature and each player.

Plague Beetle

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Patron of the Nezumi

Rat offering (You may cast this spell any time you could cast an instant by sacrificing a Rat and paying the difference in mana costs between this and the sacrificed Rat. Mana cost includes color.)
Whenever a permanent is put into an opponent's graveyard, that player loses 1 life.

Cabal Conditioning

Any number of target players each discard a number of cards equal to the highest mana value among permanents you control.

Eat to Extinction

Exile target creature or planeswalker. Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Greed

Hideous Visage

Creatures you control gain intimidate until end of turn. (Each of those creatures can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Gurmag Angler

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

Yargle, Glutton of Urborg

Blitz Leech

Flash
When this creature enters, target creature an opponent controls gets -2/-2 until end of turn. Remove all counters from that creature.

Shauku, Endbringer

Flying
Shauku can't attack if there's another creature on the battlefield.
At the beginning of your upkeep, you lose 3 life.
{T}: Exile target creature and put a +1/+1 counter on Shauku.

Necratog

Exile the top creature card of your graveyard: this creature gets +2/+2 until end of turn.

Voracious Null

{1}{B}, Sacrifice another creature: Put two +1/+1 counters on this creature. Activate only as a sorcery.

Raise Dead

Return target creature card from your graveyard to your hand.

Basal Thrull

{T}, Sacrifice this creature: Add {B}{B}.

Chime of Night

Enchant creature
When this Aura is put into a graveyard from the battlefield, destroy target nonblack creature.