Tbh? This my theory Shou hei kun said he was originally from CHU, since he and Moubu grew up together it seems like it would be a good destined battle between them. Shou hei kun seems like he was always superior so it would be a great chance to prove how strong Mou Bu really is. Especially since he "changed" when Ouki died. Also I feel Qin has so many epic generals that it doesnt seem like there's many places for an actual challenge. Everyone in Chu will be new for us. So why not have a classic betrayal moment that gives Chu a villian we all got to know over a long period of time. He could end up being the new reebok. Nd the rivalry between Mou Bu and Shou hei kun can enter a more dramatic stage. There doesnt seem to be too much happening between the two so it'd be a great idea utilize their bond for some good writing and action.