Rhystic Lightning is a common Instant card from Prophecy (PCY), collector number 99. Current market price: $0.14 (foil $0.99), TCGplayer market prices via Scryfall.
Rhystic Lightning deals 4 damage to any target unless that permanent's controller or that player pays {2}. If they do, Rhystic Lightning deals 2 damage to the permanent or player.