Beyond the human world, there existed an Alternate Dimension unbound by the laws of physics.
Infinity Castle.
This was the lair of the progenitor of demons, Muzan Kibutsuji, the manifestation of his absolute will. Countless buildings were joined, inverted, and suspended in defiance of gravity and logic. Every faint note of a biwa brought an earth-shattering rearrangement of the entire world's spatial structure.
Here, there was neither day nor night, only eternal, suffocating gloom.
Inside a Western-style laboratory in the deepest reaches of Infinity Castle, a man in sumptuous clothes, with curly black hair and an eerily handsome face, was carefully manipulating some liquid in a beaker with tweezers.
He was Muzan Kibutsuji.
His expression was focused, like a scholar immersed in his own world. The air was filled with the smell of chemical reagents and a faint scent of blood.
Finding the "Blue Spider Lily" and overcoming sunlight. This had been his sole obsession for a thousand years.
Just as he was about to add the next drop of reagent, his movements stopped without warning.
His blood-red, plum-blossom-shaped pupils contracted slightly.
In that instant just now, two "threads" closely connected to the depths of his soul had been completely torn apart by an overwhelmingly brutal force.
It was not death.
It was "erasure."
Even the traces of their existence had been burned away, evaporated, reduced utterly to nothing.
"Upper Rank... Six."
Muzan softly uttered the title.
Within his vast network of consciousness, the node representing Gyutaro and Daki had become completely blank.
A void.
A void that had never appeared in over a hundred years.
Since he had created the concept of the "Twelve Kizuki," and especially after establishing the six strongest "Upper Ranks," this group representing his greatest fighting strength had undergone no changes in membership for one