War Machine, Avenging Arsenal is a rare Legendary Artifact Creature — Human Hero card from Marvel Super Heroes Commander (MSC), collector number 63. Current market price: $0.39 (foil $7.16), TCGplayer market prices via Scryfall.
Flying Whenever War Machine attacks, attacking modified creatures you control gain double strike until end of turn. (Equipment, Auras you control, and counters are modifications.)