Of course, Zhao Hai wasn't in a hurry. So, he had put the liquid silver dust on the cultivators who went out. With their strength, they couldn't discover the liquid silver dust.
Zhao Hai had already touched the threshold of the bichen realm, so he knew what it was about. Although the bichen realm could achieve the effect of bichen, he would know even if a speck of dust fell on his body. However, it was impossible for cultivators of the bichen realm to maintain this state all the time. They could only feel the changes in the dust when they felt their own bodies with their hearts.
It was because of this that Zhao Hai could boldly use the flowing silver dust to follow them. He wanted to see who the three groups of people were.