Sky Scourer

A payoff that only functions inside a deckbuilding straitjacket: fill the deck with nothing but colorless spells, and this evasive body grows every time you cast one. The flying is what makes the pump worth anything, since a creature that swells but stays on the ground gets chumped or traded all day; in the air, each +1/+0 actually connects. The trigger watches the moment of casting, not resolution, so even a colorless spell that gets countered still adds its bonus, and the math rewards volume rather than size: four cheap colorless spells in a turn is four points of power, while one expensive spell is a single point. That pushes the build toward a low curve packed with cheap colorless interaction and creatures, not a deck top-heavy with big Eldrazi. Here devoid is the structural hinge less for this card than for everything it wants to chain around it, and the distinction matters: the trigger reads the color of the spell, not its mana cost, so a devoid spell with black pips in its cost still counts because devoid strips it to colorless on the stack. What contributes nothing is any spell that reads as colored: a plain black removal spell, a black creature without devoid. The restriction is that discipline itself, honored by leaning on devoid cards precisely because they scan as colorless despite wanting colored mana. And its own casting never counts, because the ability only reads the stack once the creature is already on the battlefield, one more wager that the no-color restriction pays off faster than the colored cards you gave up to honor it.