Brotherhood Regalia is a uncommon Artifact — Equipment card from Assassin's Creed (ACR), collector number 71. Current market price: $9.98 (foil $10.66), TCGplayer market prices via Scryfall.
Equipped creature has ward {2}, is an Assassin in addition to its other types, and can't be blocked. Equip legendary creature {1} Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)