Staggershock is a uncommon Instant card from The List (PLST), collector number IMA-147. Current market price: $0.23, TCGplayer market prices via Scryfall.
Staggershock deals 2 damage to any target. Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)