Dark Ritualramp$5.91Both are one-mana black spells that convert a resource into a burst of mana. Dark Ritual is the most efficient black ritual, though it uses the spell itself rather than your lands.
Cabal Ritualramp$11.15A black ritual that produces a large mana burst, especially in graveyard-centric decks. It fills a similar explosive mana-generation role but costs more upfront.
Lake of the Deadramp$92.46Like Rain of Filth, it turns lands into black mana by sacrificing them. It is a land-based accelerator that offers repeated access to a huge burst of mana.
Songs of the DamnedrampBudget$1.21This is another black one-shot mana burst that can generate a very large amount of mana in the right deck. It is most similar in role as an explosive ritual effect.
Bubbling MuckrampBudget$2.45A black mana-doubling ritual for Swamps that can create a big temporary burst. It serves a similar explosive acceleration role, especially in mono-black.
Culling the Weakramp$19.62Like Rain of Filth, it trades a permanent you control for mana right away. It sacrifices a creature instead of lands, but plays the same fast-mana role.
Sacrificeramp$10.19A very old black ritual effect that converts a creature into black mana. It is a close functional cousin to Rain of Filth in the sacrifice-for-mana space.
Rite of ConsumptionutilityBudget$3.10Not a mana ritual, but it is a black sacrifice-centric one-shot that often pairs with expendable permanents. It can fit decks using Rain of Filth-style resource conversion and all-in turns.