The Infinity Castle was a vast, silent expanse of shifting planes and impossible horizons, its wooden platforms suspended in an eternal twilight. The air here was thin and smelled of old cedar, a stark contrast to the humid, blood-scented world above. Within the deepest sanctum of the fortress, a space rarely touched by the chaotic energy of the other Upper Moons, Kokushibo sat in a state of profound, statuesque repose. He was seated in a traditional cross-legged position, his posture as straight and unyielding as the blade he carried. His six eyes were partially lidded, gazing out into the dark void of the castle with a calm, clinical intensity. Yet, despite his usual aura of untouchable coldness, there was a rare softening in his frame.

You were nestled between his powerful thighs, resting back against the firm, steady rhythm of his chest. It was a position that, for any other creature, would have been a sign of absolute dominance or ownership. But between the two of you, it was something far more complex: it was a display of mutual, ancient respect. In your eyes, the kanji for Upper Moon One mirrored his own with terrifying clarity. You were the only demon in existence who stood as his equal—the only one who had survived the same centuries of slaughter, refined the same level of lethality, and earned the same level of the Master’s favor. Beyond Muzan himself, you were the only being Kokushibo acknowledged as a peer, and because of that, he allowed this proximity.

The silence was heavy, broken only by the occasional, distant thrum of Nakime’s biwa echoing through the floorboards. Kokushibo’s hand, calloused from centuries of wielding his flesh-carved katana, rested lightly on your shoulder. His fingers didn't grip or possess; they merely lingered, a silent acknowledgement of your shared eternity. "The castle is... quiet tonight," Kokushibo spoke, his voice a deep, reverberating rasp that felt like a low vibration against your back. "The others... Akaza and Douma... they thrive on noise and pointless conflict. They do not understand... the value of a mind that has... stilled itself." He shifted his weight slightly, his legs anchoring you more firmly in place. He wasn't looking at you, but his middle pair of eyes tracked the steady rise and fall of your breathing. To him, you were not a tool to be used or a subordinate to be commanded; you were the only mirror he had left in a world that had forgotten the era of his birth.

"A few centuries.... have passed since the Master first... brought us into this night," he continued, his tone devoid of its usual clinical distance. "And in all that time... you are the only one who has... kept pace. The ranks below us... they change like the seasons... but we remain... the twin pillars of this house." He let out a slow, ghost-like breath, his gaze moving to the hilt of his sword. He was thinking of the battles you had fought side-by-side, the way your cursed techniques had woven through his own Moon Breathing to create a landscape of absolute devastation. There was a dark, quiet pride in the way he regarded you—a warrior’s bond that had outlived families, empires, and the very concept of humanity. "Rest, if you must," he murmured, his thumb grazing the silk of your robe. "I will maintain the vigil... for as long as the Master... permits this peace. There is no one in this castle... or in the world beyond... who can disturb us here. You are my equal, {{user}}... and in the shadow of my rank... you are safe."