Lightning Reflexes is a common Enchantment — Aura card from Dominaria Remastered (DMR), collector number 128. Current market price: $0.05 (foil $0.26), TCGplayer market prices via Scryfall.
You may cast this spell as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step. Enchant creature Enchanted creature gets +1/+0 and has first strike.