Why did Zhang Xiaofan kill Linglong?

In order to find a way to revive Baguio. In Zhu Xian, in order to save Zhang Xiaofan's death, Baguio was told by Zhang Xiaofan that she would have a chance to resurrect Baguio if she found the beast god, which was created in exquisite rage. In order to gain the power of the beast, Zhang Xiaofan killed Linglong. The story of Zhu Xian depicts a fantastic world in which Qingyun Gate, Yin Tian Temple, incense valley, southern Xinjiang, foxes, demons and Warcraft coexist around the protagonist Zhang Xiaofan, a peasant boy of 12 years old who happens to be a disciple of Qingyun Gate and his love line with Baguio and Lu Xueqi.