Su Chang'an was able to discover the brothel due to his strong abilities and his ability to sense the Eastern Demons. During the day, those beautiful women were having a meeting, their expressions were fearful, though he couldn't hear what they said, he could see the beautiful costumes with a tail.
With him as the leader, they quietly arrived at the top of the stone building. Combining the power of multiple people, they created an array that, although not very powerful, was strengthened by the collective energy of everyone.
This array might not compare to those of the Sect, but given their current capabilities, the energy that's sustained it makes the array relatively strong.
Su Chang'an first used the array plate to reinforce around the building, selecting a broad range, including the vicinity of the house, possibly the minions of these people.
