The moment Kai Syaoran disappeared, Huang Biren followed after them. She trusted him but, she also understood that he was a powerful demonic beast and his instincts led him to some of his decisions. He may suddenly decide that Huang Shengyi deserved death and that would be that.
She followed them from behind by tracking their movements through space. Kai Syaoran had no comprehensive regarding space but he was powerful enough to rip it apart. The only com prehension he had was too little to be considered a space law aspect. Besides, he now did not comprehend the laws in the same manner as other cultivators.
