Twinferno is a uncommon Instant card from Foundations Jumpstart (J25), collector number 606. Current market price: $0.23, TCGplayer market prices via Scryfall.
Choose one — • When you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy. • Target creature you control gains double strike until end of turn. (It deals both first-strike and regular combat damage.)