C86 black cloaked man

He saw Wu Daozi holding a pitch-black stone in his hand. Although it was pitch black, it was so black that it was shiny. As Nangong Shi continued to observe more carefully, the movements of the stone in the storage ring grew louder and louder.

Looks like there must be a connection between the stone in Wu Daozi's hand and the one in his ring, otherwise it wouldn't have such a huge reaction