An interesting exercise. (I assume that these are rejects from the forge). One is softer on the edge? or is the difference in damage mostly a result of the cut versus the defence?
NO, the hardness of these katana are almost equally, Big boy's edge of katana was rollen up, so Master’s katana (its edge was almost kept straight shape.) could shaved the part of rollen up. 2:59 Master mistook a defence timing and received the big boy's attack by the edge of his blade, so it occurred spark and smelled IRON. 4:26 This damage existed before its movie. 4:35 These SAW like damages were born because of the Master's "Shifting defence" again and again. And, the big boy also did "Shifting defence" before starting shot, but he was't good at the defence, it tattered the edge of his katana... NO, the hardness of these katana are almost equally, Big boy's edge of katana was rollen up, so Master’s katana (its edge was almost kept straight shape.) could shaved the part of rollen up.