These are forged from Dragon’s Soul Stones that have had two separate spaces carve out from inside them with only a thin wall left between. Nie Li then is able to fill one section with the law of light and the other with the law of darkness. Afterwards he covers them with Inscription Patterns.
When the two sections are merged it will cause a huge blast of energy. Because of the compression of the power of law, this is an even stronger version of Nie Li's Yin Yang Blast. It is also harder for enemies to dodge then the Yin Yang Blast.