Yoroi, unlike the other eleven blades, is a suit of metallic blue armor. The armor carries a ocean-motif in it's design with a conch-shell adorned behind the right shoulder, a starfish design on his shoulder, and a helmet shaped like a whale. To prove it is a real blade, the left horn of the helmet has a design similar to katana's handle.
Absolute defense is the main strength of Yoroi. The armor was designed to withstand attacks from every angle and is unaffected by armor-piercing techniques. Befitting it's position as a blade, Yoroi is covered from head to toe in hidden blades to slash the opponent while ramming into them. There is only one weakness to Yoroi in that for it to effectively block piercing attacks, the user must firmly plant their feet on the ground to absorb the shock of the attack or else it will go through.
Yoroi means armor while it's title means Bandit Sword. This fits it's wielder Azekura well, as he is a pirate.