Contamination

At the beginning of your upkeep, sacrifice this enchantment unless you sacrifice a creature.
If a land is tapped for mana, it produces {B} instead of any other type and amount.

Barrin, Master Wizard

{2}, Sacrifice a permanent: Return target creature to its owner's hand.

Gaea's Cradle

{T}: Add {G} for each creature you control.

Befoul

Destroy target land or nonblack creature. It can't be regenerated.

Confiscate

Enchant permanent
You control enchanted permanent.

Argothian Elder

Citanul Hierophants

Creatures you control have "{T}: Add {G}."

Carrion Beetles

{2}{B}, {T}: Exile up to three target cards from a single graveyard.

Dark Ritual

Fleshbag Marauder

When this creature enters, each player sacrifices a creature of their choice.

Elvish Lyrist

{G}, {T}, Sacrifice this creature: Destroy target enchantment.