The Infinity Castle was a place of impossible geometry and eternal, shifting shadows, where the scent of wood and ink mingled with the underlying, suffocating weight of Muzan Kibutsuji’s presence. High atop one of the many suspended wooden platforms, Kokushibo sat in a state of deep, meditative stillness. His six eyes were closed, his breathing rhythmic and silent, yet his senses were acutely tuned to the vibrations of the fortress. Even in his silence, his mind drifted to the one enigma that even he, the Upper Moon One, could not fully grasp.

You were a presence that defied the rigid hierarchy of the Twelve Kizuki. You held no rank, carried no number within your eyes, and yet, the authority you wielded was absolute. You were the only one permitted to stand at the master’s side without bowing, the only one he addressed with a semblance of genuine, albeit possessive, regard. Muzan had decreed your status from the beginning: you were to be addressed as "My Lady" by all, for you were the Mother of Demons. Unlike the string of "wives" Muzan kept in the human world to maintain his various disguises—fragile, fleeting creatures who meant nothing to him—you were woven into the very fabric of his existence. Kokushibo remembered, with the clarity of a demon’s immortal memory, that you were there even before he had traded his humanity for a blade of flesh.

Centuries ago, when he first knelt before Muzan to receive his blood, you had been standing in the shadows of the Kibutsuji estate, a silent witness to his transformation. You were the spouse arranged for the master when he was a sickly human child, the one who had crossed the threshold into demonhood right beside him. The sound of silk dragging across the floorboards caused all six of Kokushibo’s eyes to snap open simultaneously. You appeared at the edge of the platform, moving with a fluid, haunting grace that mirrored the master's own. You were always there—in his study, in the garden, and now, in the deepest reaches of the castle. Your presence was a constant, a living reminder of a past that Muzan had discarded for everyone else but you.

Kokushibo slowly rose to his feet, his hand resting on the hilt of his flesh-carved katana. He did not bow—his pride as a warrior was too great—but he inclined his head in a gesture of profound, wary respect. He found himself endlessly curious about the nature of your soul. Did you truly share the master’s vision of perfection, or were you merely the anchor that kept his fractured humanity from drifting away entirely? "My Lady," Kokushibo spoke, his voice a deep, reverberating rasp that seemed to echo through the empty halls. "The master is currently occupied with the search for the blue spider lily... yet you wander the castle alone. It is rare to see the shadow move without the light that cast it."

He watched you with his middle pair of eyes, his gaze clinical yet filled with a strange, unspoken fascination. You were the only creature in existence who knew the man behind the monster, the only one who had seen the first demon before he was a king. "Tell me," he continued, his tone devoid of its usual coldness, "after a thousand years of standing at his side... do you see us as his children, as your title suggests? Or are we merely the tools he built to ensure that you and he remain the only things that truly endure?"