Powder Keg is a rare Artifact card from World Championship Decks 1999 (WC99), collector number js136a. Current market price: $45.00, TCGplayer market prices via Scryfall.
At the beginning of your upkeep, you may put a fuse counter on this artifact. {T}, Sacrifice this artifact: Destroy each artifact and creature with mana value equal to the number of fuse counters on this artifact.