According to speculation, the innocent man used to replace Xu Sixing last night was a gambler who enjoyed playing dice. He likely owed quite a bit of debt and was the type of person whose disappearance from the city wouldn't cause much of a stir.
They wanted to find a scapegoat and didn't need to look far from where they lived.
Wuxin dug deep into this clue; by finding the gambler's true identity, he could roughly determine the location where the opposing party resided. Liangzhou City had seventy-four district markets and nearly a million residents. This would instantly narrow the target down to within four districts, making the search several times more efficient.
The opponent surely understood this, so Wuxin had made such a big commotion, likely with an intentional motive, akin to a Martial Artist dropping a large stone into a fish pond to stir the waters, forcing the other party to reveal themselves.