Thirty minutes earlier...
Infinity Castle was sealed off, and countless humans poured through the spatial rifts.
Their leader exuded an immensely powerful aura. Kokushibo wanted to test him, but the man merely floated to the top to watch over everything.
At his command, the humans charged forward without a care for their lives.
Kokushibo watched countless demons surge out of the gaps to meet them.
He saw Akaza face a descendant of Rengoku Shakutenko, while Doma faced three sisters and a boar.
Meanwhile, Muzan remained rooted in place, calmly enjoying their battles.
Clack!
Several humans entered the hall and approached Kokushibo's folding screen.
"According to His Majesty's description, this should be where Upper Rank One, Kokushibo, is, right?" Genya fired wildly around the room.
"Get out here!"
"Genya, over there!" Sanemi warned, pointing at the dark silhouette behind the screen.
Ratatatat! The machine gun spat sparks as he swept his fire toward it.
Whoosh! The dark silhouette darted away and vanished.
"Watch out!"
Clang! Sanemi kicked Genya away and drew his blade to block.
Only then did they get a clear look at their opponent's terrifying appearance.
The first thing they saw was the six eyes covering his face. The middle pair bore the words "Upper Rank" and "One," and his icy aura sent chills down their spines.
The long, misshapen Nichirin Blade in his hand was covered with red eyeballs, resembling a tree limb sprouting countless branches.
Had Tetsuhiro been there, he would surely have blurted out, "Isn't that the Wolf's Brush, the ultimate weapon Qi Jiguang invented to fight Japanese pirates?!"
"So you've finally arrived, Demon Slayer Corps... Good reflexes. You managed to block my [Kokushibo's Blade]."
"But that is all."
With a casual downward pull, a branching blade sliced through Sanemi's shoulder. Pain pulsed from the wound,