Dark Knight's Greatsword is a uncommon Artifact — Equipment card from Final Fantasy (FIN), collector number 95. Current market price: $0.24 (foil $0.34), TCGplayer market prices via Scryfall.
Job select (When this Equipment enters, create a 1/1 colorless Hero creature token, then attach this to it.) Equipped creature gets +3/+0 and is a Knight in addition to its other types. Chaosbringer — Equip—Pay 3 life. Activate only once each turn.