Powder Keg (UDS) from Urza's Destiny, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Dan Frazier
• Card Text:
  At the beginning of your upkeep, you may put a fuse counter on Powder Keg.
  T, Sacrifice Powder Keg: Destroy each artifact and creature with converted mana cost equal to the number of fuse counters on Powder Keg.