Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Westgate Regent

Flying
Ward—Discard a card. (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player discards a card.)
Whenever Westgate Regent deals combat damage to a player, put that many +1/+1 counters on it.

Annihilating Glare

As an additional cost to cast this spell, pay {4} or sacrifice an artifact or creature.
Destroy target creature or planeswalker.

Fetid Imp

Flying
{B}: Fetid Imp gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Gravedigger

When Gravedigger enters the battlefield, you may return target creature card from your graveyard to your hand.

Mind Rot

Serrated Scorpion

When Serrated Scorpion dies, it deals 2 damage to each opponent and you gain 2 life.

Gray Merchant of Asphodel

When Gray Merchant of Asphodel enters the battlefield, 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.)

Typhoid Rats

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Murder

Phyrexian Rager

When Phyrexian Rager enters the battlefield, you draw a card and you lose 1 life.

Squelching Leeches

Squelching Leeches's power and toughness are each equal to the number of Swamps you control.

Unnatural Endurance

Devoid (This card has no color.)
Target creature gets +2/+0 until end of turn. Regenerate it.