Duskmourn: House of Horror Commander

Leechridden Swamp

({T}: Add {B}.)
Leechridden Swamp enters tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Jumpstart 2022

({T}: Add {B}.)
Leechridden Swamp enters the battlefield tapped.
{B}, {T}: Each opponent loses 1 life. Activate only if you control two or more black permanents.

Duel Decks: Nissa vs. Ob Nixilis

({T}: Add {B} to your mana pool.)
Leechridden Swamp enters the battlefield tapped.
{B}, {T}: Each opponent loses 1 life. Activate this ability only if you control two or more black permanents.

Planechase

Shadowmoor

({T}: Add {B} to your mana pool.)
Leechridden Swamp comes into play tapped.
{B}, {T}: Each opponent loses 1 life. Play this ability only if you control two or more black permanents.