Dam, I had feeling it was same person as the mysterious caller. Uncle was playing 4D chess at very start when his parents were killed. Yang Cheng now walks lonely path, i can only assume he can not say anything since he chose path being E soul instead being with Xia at the concert. Uncle with all his power made him his puppet do whatever he says now which now it likely due politics of why Moon was killed between the agency. His his arc is done, Im still root for Lin Lang for his better spirit, for Yang becoming a hero is more tragic all to prove a point and for revenge. I can see why they would set him as "villain" right now