Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Carmen, Cruel Skymarcher

Flying
Whenever a player sacrifices a permanent, put a +1/+1 counter on Carmen, Cruel Skymarcher and you gain 1 life.
Whenever Carmen attacks, return up to one target permanent card with mana value less than or equal to Carmen's power from your graveyard to the battlefield.

Culling the Weak

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

Soldevi Adnate

{T}, Sacrifice a black or artifact creature: Add an amount of {B} equal to the sacrificed creature's mana value.