Steel Release: Impervious Armour

This technique allows the user to turn part of their body into black steel, making that part invulnerable to most kinds of weapons. Hiruko states that blades do not affect him at all due to this ability. The portion converted into black steel is similar in appearance to Kakuzu's Earth Spear technique. Hiruko uses it to counter Sai's tantō, causing it to snap clean in half on impact.