Li Shentan had thought that if he offended the Lian tribe's chief, she might retaliate with a series of actions against him, such as tying him to a wooden stake and whipping him, or hanging him up and refusing to give him any water to drink.
But he was not afraid of that. The people from the Lian tribe had underestimated his power of hypnotism and thought they could really place him under captivity with these copper and silver corpses.
If they actually attempted to kill him, the people from the Lian tribe would get defined as "bad people" in Li Shentan's mind, and he would not feel any guilt about hypnotizing them to join the Prosperous Northwest together.
Li Shentan had promised Ren Xiaosu to be a good person and live with a ray of light in his heart. As such, everything he did now would have to be based on this philosophy and match its logic, so he could not hypnotize the good people, only those who were bad.