Blade of Shared Souls is a rare Artifact — Equipment card from Phyrexia: All Will Be One Promos (PONE), collector number 42p. Current market price: $0.33 (foil $0.25), TCGplayer market prices via Scryfall.
For Mirrodin! (When this Equipment enters, create a 2/2 red Rebel creature token, then attach this to it.) Whenever this Equipment becomes attached to a creature, for as long as this Equipment remains attached to it, you may have that creature become a copy of another target creature you control. Equip {2}