Break his arm

But Luo did not say it. He did not say anything. The silence enveloped them once more, broken only by the howling wind and the groans from Master Lee. Luo Muchen remained resolute, his silence a defiance that echoed louder than words. Master Zi, seething with impotent rage, released his chin, his eyes burning with hatred. 

He had finally realised that the relationship between father and son wasn't good. Luo Muchen would rather watch his father suffer and not do anything about it. He could have eased Master Lee's pain by saying the words but he didn't even open his mouth. In Luo Muchen's heart, his father was just like his mother who abandoned him. His father knew he existed and didn't have the intention to claim him. It was only when he wanted to use him that he came looking for him.