When Chittering Rats enters the battlefield, target opponent puts a card from their hand on top of their library.

{T}: Cuombajj Witches deals 1 damage to any target and 1 damage to any target of an opponent's choice.

When Gray Merchant of Asphodel enters the battlefield, 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.)

When Phyrexian Rager enters the battlefield, you draw a card and you lose 1 life.

Destroy target nonlegendary creature.

Target creature gets -1/-1 until end of turn for each Swamp you control.

Target player sacrifices a creature and loses 1 life.

Barren Moor enters the battlefield tapped. {T}: Add {B}. Cycling {B} ({B}, Discard this card: Draw a card.)

Bojuka Bog enters the battlefield tapped. When Bojuka Bog enters the battlefield, exile target player's graveyard. {T}: Add {B}.

({T}: Add {B}.)

Target player sacrifices a creature. Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Destroy target non-Swamp land. If that land was nonbasic, Choking Sands deals 2 damage to the land's controller.

Choose one — • Target opponent exiles a creature they control. • Target opponent exiles an enchantment they control.

Target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)

{T}, Sacrifice Nihil Spellbomb: Exile target player's graveyard. When Nihil Spellbomb is put into a graveyard from the battlefield, you may pay {B}. If you do, draw a card.

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.) Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

Target player sacrifices a creature. Flashback {5}{B}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

{X}: Crypt Rats deals X damage to each creature and each player. Spend only black mana on X.

Target player sacrifices a creature and loses 1 life.

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.

Put a +1/+1 counter and a lifelink counter on target creature.