Zhao Hai had been thinking about when he could use the yin-yang pool on common magical weapons made of liquid silver, such as sword-shaped magical weapons. That way, his magical weapons would be more powerful.
However, if the yin-yang Lake was placed in one of those magical artifacts, it would become smaller, which would affect the energy output of the yin-yang Lake. Thus, Zhao Hai had not done so.
But now, Zhao Hai wanted to do so because of the Thunder pool. The Thunder pool was different from the yin-yang pool. The yin-yang pool absorbed energy from the outside and then released it into the yin-yang pool.
But the Thunder pool was different. The power it produced was due to the yin and yang lightning in it. Although some of them could be put together, these two types of lightning existed in a cycle, without beginning or end. They could produce very powerful energy by themselves, and once this energy was released, it could naturally be used.