把她带到奶刑室用乳刑折磨

On the contrary, it is more likely that Yin Kongchan did it. Yin Kongchan took Ning Cheng's ring and thanked Ning Cheng for saving her several times. He knew how to repay his kindness, so he spared Ning Cheng's life. Even because he obtained the Nine Yin Essence of the Earth's Core, he didn't even take away Ning Cheng's Sky Cloud Wings....