About a dozen years ago, a terrifying legend began circulating in Konoha.
The legend said that a massive complex existed within Konoha's shadows, filled with all kinds of research facilities.
The figures of dead ninja, dressed in white burial robes, endlessly wandered its halls, carrying out their horrifying research. These ninja, bewitched by malice, sought to break free from the prison of life and death and longed to return to the land of the living.
Yet those who lived in the shadows were bound by the limits of time and life. They could not freely walk beneath the light, and could only use medicine and Physical Bodies to conceal their decaying souls. But when their time came, the substance of their souls would separate from their bodies, forcing them back into the shadows.
More terrifying still, these monsters were, in a sense, still alive. They possessed normal minds and thoughts, and might even be hiding among the people around you, smiling as they listened to your conversations. Then, one night, a friend who had long since left in your hazy memories and had finally returned would appear in your room, smiling as he asked whether you wanted to join them.
Only then would you jolt awake from the nightmare, realizing that your former friend, that former warmth, had already been dead for decades.
This rumor had circulated in Konoha for a long time. Because it was so close to the lives of ninja and felt so real, parents often used it to frighten disobedient young ninja, usually with remarkable results.
For ninja, there was nothing more terrifying than this. Their former coworkers, friends, and comrades might have died without their knowledge, only for an enemy to take on their face and turn their thoughts against them.
In the ninja world,