Ephemeral Shields is a common Instant card from The List (PLST), collector number M15-11. Current market price: $0.23, TCGplayer market prices via Scryfall.
Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.) Target creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)