well i have been puzzled by rings on the back of a sword. I don't remember rings on the back of any european sword. They had on some edged weapons slots to catch a sword. So why in China would you have rings. One thing is the influence of Buddhaism. If they didn't do anything they would be found around the hilt and probably very small. The antique that I have has some thick rings nearly all the way to the point. Definitely functional. One thing they would prevent is cutting so deep that you would have a dead body hanging off of the blade or a live one hanging on and draging you down. You only cut as deep as the width of the blade and stab as long as the point. I can see where someone could get med enough to take a sword to the body while his buddies hack the swordsman to death. If you use the rings as a secondary grip you can slam with the handle end or the point just like the old time battering ram. Use the edge to scrape someones face off. Chop and twist breaks off big pieces of sharp bone on the head or shins. In close grapling combat you would have leverage and speed holding both ends of the sword. The broad hooked point on my sword stuck in the armpit and twisting into a hip throw is a nice close range crowd pleaser. Using a ringed sword for short medium and long attacks would leave the battle field looking like a tiger had been there. The nine rings would be a reminder of Buddha have mercy on the people left maimed and dead.