Rebirth and Tong Yisheng

Before rebirth, Qiu Tong was a very bad woman and was a sworn enemy of Ye Yuchen. In the end, Qiu Tong died to save Ye Yuchen. After rebirth, Ye Yuchen wanted to be good to Qiu Tong and make her happy. But who told him that the sister he taught so well turned evil in the end?