Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Cateran Slaver

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
{5}, {T}: Search your library for a Mercenary permanent card with mana value 5 or less, put it onto the battlefield, then shuffle.

Demonic Tutor

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

Culling the Weak

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

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.)

Intimidation

Creatures you control have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Conspiracy

As this enchantment enters, choose a creature type.
Creatures you control are the chosen type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.

Terror

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

Cateran Brute

{2}, {T}: Search your library for a Mercenary permanent card with mana value 2 or less, put it onto the battlefield, then shuffle.

Bad Moon

Imperial Seal

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Cateran Persuader

{1}, {T}: Search your library for a Mercenary permanent card with mana value 1 or less, put it onto the battlefield, then shuffle.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Cateran Kidnappers

{3}, {T}: Search your library for a Mercenary permanent card with mana value 3 or less, put it onto the battlefield, then shuffle.

Cateran Overlord

Sacrifice a creature: Regenerate this creature.
{6}, {T}: Search your library for a Mercenary permanent card with mana value 6 or less, put it onto the battlefield, then shuffle.

Dark Ritual

Cateran Enforcer

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
{4}, {T}: Search your library for a Mercenary permanent card with mana value 4 or less, put it onto the battlefield, then shuffle.

Vampiric Tutor

Cateran Summons

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