The air in the chamber was a thick, suffocating haze of pulverized wood and the metallic tang of blood. Kokushibo stood amidst the ruins, his breathing heavy—a sound like tectonic plates grinding together. His kimono was tattered, and for the first time in centuries, the indomitable Upper Rank One felt the cold creeping sensation of mortality. He had just witnessed it. The moment of true horror. In the polished, blood-slicked steel of Sanemi Shinazugawa’s blade, Kokushibo had seen a glimpse of his own reflection.

It wasn't the proud, transcendent samurai he imagined himself to be. It was a monster. A creature with six eyes and a face distorted by a pathetic, centuries-old grudge. The shock of it had sent a tremor through his very soul, his grip on his flesh-warped katana faltering as the image of the man he once was—Michikatsu—flickered and died in that reflection. His body began to crumble, the cell regeneration slowing as his will to live wavered under the weight of his own hideousness. Is this... what I became? he thought, his vision blurring. A creature... so foul... that even the blade... rejects my image? But as the ash began to flake from his fingertips, a sudden, sharp clarity pierced through the despair.

You.

His six eyes snapped wide, the pupils dilating with a primal, desperate intensity. Somewhere else in this shifting, chaotic fortress, you were fighting. You—the other Upper Rank One, the only being who sat at his side as an equal—were still out there, surrounded by the same desperate, ravenous slayers that were currently tearing him apart. If he fell here, who would stand between you and the sun? If he perished, who would ensure that your shared eternity didn't end in a pile of gray dust on a wooden floor? The thought of you being cornered, of a Nichirin blade touching your throat while he wasn't there to cleave the world in two for you, acted like a bolt of lightning to his failing heart. "No..." Kokushibo’s voice was a low, guttural snarl that vibrated through the very foundations of the Infinity Castle.

The crumbling stopped. The flesh on his neck and torso began to knit back together with a violent, wet sound, the bone reforming with even greater density than before. He ignored the reflection in Sanemi’s sword, turning his gaze back to the Hashiras with a look of such absolute, terrifying resolve that even the air seemed to freeze. "I cannot... fall..." he rasped, his voice regaining its ancient, monolithic power. "Not yet... Not while... you... are still... in this place." He swung his blade, a massive crescent of chaotic, moon-shaped energy erupting from the steel, forcing Sanemi and Gyomei back. His focus was no longer on his own monstrous face or his brother's memory. It was on the tether that bound his soul to yours. He would become a demon a thousand times more hideous if it meant surviving long enough to reach your side. "I will... endure..." he whispered, his eyes burning with a possessive, protective fire as he prepared to unleash a level of violence the castle had never seen. "I will not... leave you... alone... with these... insects."