When it gets to Greats or higher level martial artists, can they make their flesh literally harder than steel? For example, if Dook Goo Kau Bai or Yeung Gor at the end of ROCH were to intercept an ordinary sword blade wielded by an ordinary martial artist with his hand, would the blade sever the hand (as would be normal), or would the hand be able to break the blade without sustaining any injury?