Xue Sheng
All weight is underside
The funny thing is I'm almost certain it is aluminum
They do make Chinese broadswords out of it at least i think
I could make some guesses why but ill wait to see if someone else posts, they may know more
The one in the video is what they refer to as Wushu steal... it is actually more like a spring steal than an aluminum, it makes a loud noise wen you thrust it and it looks a sounds really cool for preformance, but beyond that it ain't worth much.
A good friend of mine (retired LEO) who was a Aikido/Kendo/Karate guy referred to those type of Chinese weapons as Boing Boing Flap Flap swords.