"Legend has it that in ancient Japan, they used to rate swords by how many bodies they could cut entirely through with one stroke"
Not a legend- It is real. The bodies were stacked on a mound of sand, and special testers would try the swords. There are books extant with the cut diagrams illustrated. Through the pelvis was considered the most difficult from what I remember. Some swords were inscribed on the tang with the cutting test info, such as "Cut two bodies with one stroke", etc.