Rebel Salvo is a uncommon Instant card from Phyrexia: All Will Be One (ONE), collector number 144. Current market price: $0.28 (foil $0.24), TCGplayer market prices via Scryfall.
Affinity for Equipment (This spell costs {1} less to cast for each Equipment you control.) Rebel Salvo deals 5 damage to target creature or planeswalker. That permanent loses indestructible until end of turn.