Heralds of Tzeentch

Cascade at five mana value is a deliberately restrained roll of the dice: the trigger hunts for something cheaper than five, which in practice means a free spell somewhere below five mana, cast off the top of the deck without paying for it. That restriction is doing all the work. A flying 3/3 body is unremarkable on its own, so the card is really a delivery vehicle for whatever your curve happens to spit out, and the ceiling scales entirely with how disciplined your mana values are below the five slot. Load the deck with high-impact four-drops and the cascade becomes a second haymaker stapled to an evasive creature; run a scattered, top-heavy curve and it whiffs into a random cantrip. The flavor of the mechanic fits the Tzeentchian theme neatly: cascade is chance dressed up as scheming, a random reveal that the caster is nonetheless meant to have engineered in advance. Where older cascade cards leaned red or multicolored, putting the keyword on a mono-blue flier is the quiet novelty here, since it hands blue a form of raw card advantage that sidesteps the color's usual draw-and-counter idiom. The value is real but never guaranteed, which is precisely the point of building around a mechanic whose reward you can shape but never fully name in advance.