Li Xuan had exchanged Deity Transformation Stage blood slaves for these Eyes of the Blood Demon. There was only one pair, and both were used to monitor Jiang Qingyu.
One was kept in plain sight. Li Xuan knew that Jiang Qingyu was as sharp as his younger sister, so he knew his tricks would be seen through quickly. Therefore, he had placed another one in the shadows, protected by an array. That array served only to stop anyone attempting to destroy the Eye of the Blood Demon; it would cause no harm to the eye itself.
The outer array consisted of an isolation barrier combined with a trapping formation. It masked her presence so that no outsider could detect her, and it ensured she could not escape.
Chapter 40