Zhao Hai knew that once the destroyers appeared, they would use the power of destruction when they fought. If they didn't use the formation, the commoners and the city walls wouldn't be able to stop it. Under such circumstances, the best way to reduce the casualties of the commoners was to use the formation.
The situation on the Inhumans 'continent was different from that of the spiritual weapon world. Although there were occasional Wars in the Inhumans' continent, the scale of the wars were not very large. Furthermore, it was not like the spiritual weapon world where there were years of war. This resulted in the population on the Inhumans 'continent to be much higher than that of the spiritual weapon world.
