Darkrooms were a fictional concept, not a real place. It originated from a forum discussion post that described the story of people trapped in an endless space of horror. Later, this concept was used to create media works such as games, animations, and short films. The darkroom was described as a maze of randomly generated rooms with a damp smell, yellow walls, and buzzing fluorescent lights. There were also some hostile existences known as " entities " inside. However, it was important to note that the darkroom was only fictional and not a real place.
Sure is. The Backrooms is a creation of imagination found in various online communities and horror-related content. It doesn't have a basis in reality.
Inosuke doesn't become a Hashira in the manga. The story progresses with him having other significant experiences and achievements instead of achieving that specific position.
It's hard to give an exact number. Different story arcs and battles led to the deaths of multiple hashira. Some died heroically, while others met their fate in unexpected ways. The count changes as the manga progresses.