Deadly Designs is a uncommon Enchantment card from Conspiracy: Take the Crown (CN2), collector number 42. Current market price: $0.15 (foil $0.51), TCGplayer market prices via Scryfall.
{2}: Put a plot counter on this enchantment. Any player may activate this ability. When there are five or more plot counters on this enchantment, sacrifice it. If you do, destroy up to two target creatures.