Void

Pick a number and the whole battlefield bends around it. The design here is the single-axis sweep: instead of destroying creatures by color, by power, or with a damage threshold, this hits everything sharing one mana value, artifacts and creatures and the cards still hiding in a hand. The number you choose becomes a scalpel and a hammer at once. Call three and you sweep the midrange creatures, blow up the mana rocks built on three, and strip the three-drops out of an opponent's grip before they can deploy them. The genius of keying off mana value is that it makes the card a single, devastating answer to whatever a deck is structured around: most decks cluster their threats at one or two points on the curve, and Void lets you collapse a column. The cost is that you only get one number per casting, so the card rewards reading the opposing list and punishes a misread. It pairs the two destructive impulses of black and red into a tempo and resource haymaker: board wipe and hand attack resolving off the same choice, on the same turn. That double duty is why it has never been a clean sweeper or a clean discard spell; it is both, narrowed to a single point on the curve, and that narrowing is exactly what makes a well-aimed cast feel like robbing someone twice.