Sword of Kaldra is a rare Legendary Artifact — Equipment card from Mirrodin Promos (PMRD), collector number 251★. Current market price: — (foil $31.89), TCGplayer market prices via Scryfall.
Equipped creature gets +5/+5. Whenever equipped creature deals damage to a creature, exile that creature. (Exile it only if it's still on the battlefield.) Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)