Legacy Weapon is a mythic Legendary Artifact card from Dominaria Remastered (DMR), collector number 450. Current market price: $0.48 (foil $1.00), TCGplayer market prices via Scryfall.
{W}{U}{B}{R}{G}: Exile target permanent. If Legacy Weapon would be put into a graveyard from anywhere, reveal Legacy Weapon and shuffle it into its owner's library instead.