Vengeful Archon is a rare Creature — Archon card from Magic 2011 (M11), collector number 37. Current market price: $0.25 (foil $0.50), TCGplayer market prices via Scryfall.
Flying {X}: Prevent the next X damage that would be dealt to you this turn. If damage is prevented this way, this creature deals that much damage to target player or planeswalker.