Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Dark Ritual

When Ashen-Skin Zubera dies, target opponent discards a card for each Zubera that died this turn.

When Floating-Dream Zubera dies, draw a card for each Zubera that died this turn.

Sacrifice a creature: Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Carrion Feeder can't block.
Sacrifice a creature: Put a +1/+1 counter on Carrion Feeder.

When Ember-Fist Zubera dies, it deals damage to any target equal to the number of Zubera that died this turn.