The white-clad fairy's name was Mu Jiuxian, the granddaughter of the leader of the Yiqi Dao Alliance.
The black-clad woman, on the other hand, was no less significant. Her name was Su Jinyao, the saintess of the Wanmo Shrine.
The reason Mu Jiuxian was pursuing Su Jinyao wasn't due to any enmity between the Yiqi Dao Alliance and the Wanmo Shrine. In fact, the relationship between these two forces, while not exactly friendly, had never been particularly hostile either.
It was because of something Su Jinyao had done that infuriated Mu Jiuxian, prompting the usually aloof Mu Jiuxian to abandon her cultivation and chase her across millions of miles in just a few days, determined to bring her to justice!