That person's subtle movements were extremely well-concealed; if one were not paying attention, one might easily mistake them for normal fluctuations of Yin energy.
However, the moment Bai Mengjin entered Wangchuan Forest, she had spread out her spiritual sense, keeping a constant watch on every movement around her. Coupled with the assistance of the Yin-Yang Umbrella, not even the tiniest ripple of Yin energy could escape her notice.
"Tinkle, tinkle..." The crisp, pleasant sound of Suiyu clashing echoed, and in the blink of an eye, it enveloped that cluster of Yin energy.
Chapter 489