Big spells are going to be very juicy for this, of course, but also small things like counterspells and other interaction will get the damage flowing
It's good in literally any deck with a lands theme, turning simple cards like Evolving Wilds into useful tools
Indestructible is good, too
Avatar: The Last Airbender - Firebending Winner: Firebender AscensionFirebender Ascension Runner-up: Sozin's CometSozin's Comet To firebend X, the creature adds X to its controller's mana pool when it attacks, and this mana lasts until end of combat
You can cast a spell using flashback even if it was somehow put into your graveyard without having been cast
If an ability triggers "whenever you tap" something for mana and produces mana, that triggered mana ability won't be affected by Nyxbloom Ancient