Mask of Avacyn

Most equipment buys offense; this one buys insulation. The +1/+2 is small enough to fade into the background, because the real payload is hexproof: bolt the mask onto a creature and the targeted removal in your opponent's hand turns into dead cards. That reframes the whole exchange. Spot removal is the most efficient interaction in the game, and an equipment that voids it for three mana per attachment makes every kill spell they drew a tempo loss instead of a trade. The split between a cheap cast and a heavier equip cost is the lever doing the balancing: you can deploy the artifact early and hold it, but committing it to a creature is a real investment that an opponent can punish by killing the body in response, before the equip resolves, or simply by ignoring the protected threat and racing. Hexproof also cuts both ways at the design level: it shields your creature from your opponents while leaving your own auras, pumps, and sacrifice triggers free to land, which is exactly why a granted-protection equipment reads differently from hexproof printed onto a creature itself. The mask is portable. Lose the carrier and you re-equip the next one, making it a recurring tax on a removal-light opponent rather than a one-time blank. It is the quiet kind of resilience that does not win a game by itself but makes the creatures that do nearly impossible to interact with on the cheap.