Tumble Magnet

A Fog you have to ration. Where a spell that taps an attacker is gone the moment it resolves, this colorless artifact banks three uses into a single body and spends them one at a time, which changes how you hold it. Each charge buys you a tempo swing: tap the biggest creature before combat and the alpha strike comes up a body short, tap a mana rock or an attacker on the crackback, then do it twice more before the thing is spent. The constraint that pays for the repeatability is the tap on the artifact itself, so it answers one threat per turn cycle and never two; it cannot stop a board that goes wide, only a board that leans on a single must-deal-with creature. The other quiet design choice is that it taps artifacts as well, an early hint of a set's preoccupation with the type that gives the card a second life as a soft answer to mana rocks and pingers. Colorless availability is the rest of the appeal: any deck can run a three-counter defensive clock without bending its colors, which is why this style of charge-counter blocker keeps reappearing in decks that want to stall without paying a color tax for the privilege.