In this corrosive downpour, many man-made shells that came into contact with the hazy drizzle gradually began to corrode. If it weren't for the fact that the rain didn't erode stones, the civilization that had been restored might have been destroyed once again.
No one knew that this corrosive rainfall was not a true natural disaster, and its coverage was actually limited to the area around Magic Capital Base only.
The reason why this corrosive rain suddenly appeared was due to the actions of the Bat Monsters that fled after the appearance of that giant creature.
On the other side of the Plane Transmission Channel, there is also a complete civilization which has undergone the same experiences as the Blue Star at this time, enduring a series of different natural disasters, with interdimensional invasions interspersed in between.