The buzzing sound that rang out at this moment was the warning from the formations. Whenever the soldiers standing watch on the city wall noticed anything amiss, they would sound the alert at once.
The soldiers here were divided into five groups of ten. At present, a Nascent Soul cultivator was leading one team on patrol outside.
Since the defensive perimeter only stretched a few hundred li, the cultivators patrolling atop the wall merely needed to take turns sweeping the surroundings with their Divine Sense. There was no need to patrol in flight.
With a Nascent Soul cultivator's Divine Sense intermittently probing the area as well, that was enough to detect most abnormalities.
Under normal circumstances, Li Yan and Mu Guyue would likewise strengthen their surveillance of the surroundings from time to time.
The formations here, large and small, could only be activated by the patrolling soldiers using tokens to issue warnings when something happened. Only Li Yan and Mu Guyue could truly control the main formation.
Mu Guyue still felt this method of patrol was somewhat passive. That was why they had marked locations on the map earlier—they wanted to set up small formations at several critical points.
These formations would mainly trap enemies and sound warnings. However, they made no distinction between friend and foe, so their own scouts secretly advancing ahead might also stumble into them by mistake.
Mu Guyue believed that the Azure-Armored soldiers previously stationed here had probably considered this method as well, but had ultimately been unable to implement it. They would need to find a way to solve that problem.
The simplest method was naturally to notify the army in the rear, but scouts being captured was far from uncommon.
Once the enemy performed a Soul Search, those formations would become completely useless