Smoke Bomb is a uncommon Artifact card from Assassin's Creed (ACR), collector number 75. Current market price: $0.36 (foil $0.38), TCGplayer market prices via Scryfall.
Flash All creatures have shroud. (They can't be the targets of spells or abilities.) At the beginning of your upkeep, sacrifice this artifact. When you do, target creature you control can't be blocked this turn.