Steel Release: Impervious Armour

This technique allows the user to turn their body into jet-black steel. Hiruko states that blades do not affect him at all due to this ability, which is demonstrated when Sai's tantō snapped clean in half on impact.

Trivia

 * The portion converted into jet-black steel is similar in appearance and functionality to Kakuzu's Earth Spear technique, though Hiruko did not show the offensive usage.