"They were perfectly ordinary Japanese sliding doors. But they appeared without warning. When I struck them with my Nichirin Blade, I felt no sensation of the blade hitting anything solid. Once struck, those paper doors instantly dissolved into black smoke and vanished. But around a corner, in a blind spot on another street, identical paper doors would form again."
After hearing this, all the Hashira looked extremely grave.
The spatial phenomenon that completely defied the laws of physics, along with the Probe Eyeballs bearing the character for "Four," all pointed to one terrifying fact.
Rokuya stepped forward. He looked down at the eyeballs marked "Four," his gaze becoming extraordinarily deep. Without hesitation, he delivered an utterly certain conclusion.
"After Hantengu died, the position of Upper Rank Four was left vacant. These eyeballs marked 'Four' belong to the demon who replaced Hantengu as the new Upper Rank Four." Rokuya's voice was exceptionally calm, reaching everyone's ears clearly.
Rokuya raised his head and looked around at the Hashira.
"Her Blood Demon Art should be spatial manipulation." Rokuya laid out the information. "Those strange paper doors aren't illusions at all. They're spatial projections of Infinity Castle, Muzan's ultimate trump card for the final battle."
"Infinity Castle?" The Water Hashira, Giyu Tomioka, frowned and repeated the utterly unfamiliar name.
"Yes, that's the name I gave that Blood Demon Art." Rokuya continued with absolute certainty. "It's a massive extra-dimensional fortress capable of completely overturning the rules of space and gravity. Inside are countless disordered rooms, stairways, and corridors. Muzan has been hiding there all along. Those paper doors are entrances to that extra dimension."
Rokuya turned to Kagaya Ubuyashiki.
"Oyakata-sama, the situation is perfectly clear now." Rokuya spoke very quietly, but his voice was heavy. "Using these eyeballs and paper doors, the new Upper Rank