I just can't see Kanki getting out of this alive, with him alive Qin will not be able to rule over the citizens of Zhao peacefully. I hope he sacrifices himself to take down Riboku, with that you hit two birds with one stone, gain the acceptance of the citizens of Zhao, and get rid of the biggest obstacle to the unification of China, Riboku.
+ With Kanki gone I'm sure his army will join Shin's, since he was a slave and all they might relate to him and accept him as their new General.