The Spinning Sphere is a technique invented by Ryun, after three years of development. The Spinning Sphere is still a very useful, difficult to learn, energy attack. As Goku trained Ryun how to use it, learning the Spinning Sphere was broken into three steps. The first was to burst a balloon by spinning the air inside in multiple directions at once using only the user's ki, which emphasizes rotation. Then the user needs to burst a rubber ball, and since rubber is thicker and air is completely different, it forces the user to use denser ki to break it, this step emphasizes power. The last is to combine steps one and two by spinning ki inside a balloon without making it move at all.
The energy spinning at such a speed and compacted into such a small state allows the technique to grind whatever it comes in contact with, causing major damage to it, and can even cause internal damage. And because the Spinning Sphere is just pure energy, it doesn't have a definite limit of use like its counterpart.