Big Mana decks aim to produce far more mana than a normal curve requires, then turn that surplus into enormous creatures, expensive spells, or scalable X-cost effects.
Cabal Coffers produces increasing amounts of black mana as your swamp count grows, Nyxbloom Ancient triples mana production, and Commander all-star Exsanguinate converts a huge stockpile of mana directly into mass life loss and life gain.
