For fuck's sake Riboku, just slaughter this army of sodding degenerates already. This is literally an army of murderous, sadistic rapists that you have at your mercy.
You would be doing the world a favour by putting these mad dogs down but you are negotiating with them even though you can just achieve whatever objective you want right now?
I guess he still could be worried about Kanki dying in the resulting melee but honestly, why should he care? Leaving Kanki alive under any circumstances is just an all round bad idea.
The average Zhao citizen is pissed because you didn't bring the mass murdering rapist to justice. That is the first and foremost reason to begin with.
I swear Kanki's real Great General power is that he telekinetically steals the brain power of all his opponents.