This technique could cover an extremely large area and carry out extremely detailed surveillance. Any place where the power of the Nine Nether appeared would be discovered, and it would immediately appear on the light screen at the center of the array. Even if a small amount of Nine Nether power appeared, it would be detected.
It was very accurate.
There had never been any mistakes.
However, to set up the Human Dao Demon Sealing Array, one had to gather the luck of all the people in the world.
In other words, if he wanted to use the Human Dao Demon Sealing Array to monitor this Immortal Land in all aspects, he had to first unify all the human forces in the Immortal Land.
Cui Heng emphasized this to Hong Fugui.
Hong Fugui knew Cui Heng's worries very well. He nodded solemnly and said, "Teacher, don't worry. I've been preparing to take action since 20 years ago. Now is the best time."