This explosive loop begins the moment Sozin's Comet enters the battlefield and its firebending 5 ability turns your attackers into miniature ritual engines, showering you with red mana every time they declare an attack. Normally that mana would vanish into thin air as phases shift, but Upwelling acts as the ultimate reservoir, letting your unspent resources bank up safely across turns and steps. Once you’ve accumulated enough wealth from those fiery strikes, you can pump it directly into Aggravated Assault to untap your entire board and rip through an endless succession of extra combat phases, turning every single attack into fuel for the next.