Why did Ji Ruochen destroy Ling Xue?

Asked the host. In the 22nd episode of TV series, Master Wei Zi admonishes Ji Ruochen, pointing out that he is the choice of fate. Only by destroying the Shura Pagoda and Lingdong in the Nine Wonders can we purify the bright flame of the orchid again and restore the tranquility of the Three Realms. Ji Ruochen got the method to destroy the Shura Tower and Lingdong from the master.