Netherworld

The, also referred to as The Nether is an evil and forbidden area of the Tokyo Empire.

In reality, it is simply the remains of the underground train network underneath the nation that was mainly destroyed during the Great Cataclysm.

Overview
In the Church's teachings, the underground landscape is an unclean hell for not receiving the light of the Sun God. By the law of the Tokyo Empire, it is strictly forbidden for anyone to enter the Netherworld. Entrance and exploration of tunnels requires approval from The Holy Sol Temple, and even with permission from the church, it is still considered a horrible taboo.

The Netherworld is filled with fallen rubble and old trains that haven’t ran in well over two centuries. Though the old train lines and stations have long since fallen into disrepair, a few areas, such as the area around Yotsuya Station, still has functioning electricity and machines. Despite theoretically just being old train tunnels, there are temples and churches all through the area, though they were mostly likely built at some point after the tunnels were abandoned.

Due the sheer size of the tunnel network and the fact that it spreads all over the Tokyo Empire, it contains many secrets and is utilized by certain organizations.

Despite the official beliefs of the Tokyo Empire, the government and church have various uses for the Netherworld. The Holy Sol's Shadow, a group of orphans taken in by the church and raised as assassins, are raised underground in the Netherworld and are trained for life in the darkness to secretly protect the nation's, or more specifically the churches, interests.

The White-Clad also use the Netherworld as a base of operations. Due to it being forbidden territory, they usually don’t have to worry about anyone finding them, and if someone does come, The Knights of the Ashen Flame are able to make good use of the underground environment to take down their opponents.

It is believed that if every Pillar was to be gathered here, then the Evangelist would be unable to reach them, due to her inability to enter the Netherworld.