Withering Boon

As an additional cost to cast this spell, pay 3 life.
Counter target creature spell.

Ashen Powder

Put target creature card from an opponent's graveyard onto the battlefield under your control.

Urborg Panther

{B}, Sacrifice Urborg Panther: Destroy target creature blocking Urborg Panther.
Sacrifice a creature named Feral Shadow, a creature named Breathstealer, and Urborg Panther: Search your library for a card named Spirit of the Night, put that card onto the battlefield, then shuffle.

Breathstealer

{B}: Breathstealer gets +1/-1 until end of turn.

Mangara's Tome

When Mangara's Tome enters, search your library for five cards, exile them in a face-down pile, and shuffle that pile. Then shuffle your library.
{2}: The next time you would draw a card this turn, instead put the top card of the exiled pile into its owner's hand.

Spirit of the Night

Flying, trample, haste, protection from black
Spirit of the Night has first strike as long as it's attacking.

Feral Shadow

Forsaken Wastes

Players can't gain life.
At the beginning of each player's upkeep, that player loses 1 life.
Whenever Forsaken Wastes becomes the target of a spell, that spell's controller loses 5 life.

Shauku, Endbringer

Flying
Shauku, Endbringer 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.

Shallow Grave

Return the top creature card of your graveyard to the battlefield. That creature gains haste until end of turn. Exile it at the beginning of the next end step.

Tombstone Stairwell

Cumulative upkeep {1}{B} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
At the beginning of each upkeep, if Tombstone Stairwell is on the battlefield, each player creates a 2/2 black Zombie creature token with haste named Tombspawn for each creature card in their graveyard.
At the beginning of each end step and when Tombstone Stairwell leaves the battlefield, destroy all tokens created with Tombstone Stairwell. They can't be regenerated.

Purraj of Urborg

Purraj of Urborg has first strike as long as it's attacking.
Whenever a player casts a black spell, you may pay {B}. If you do, put a +1/+1 counter on Purraj of Urborg.