Time flows relentlessly, years passing like a fleeting steed. Since Yoriichi's passing, the days have slipped by as if in a dream.
The brothers who once guarded the valley, carried away by time's current, grew old and passed from this world.
Yet their bloodline endured. Their descendants took up their mantle, becoming the valley's new protectors, steadfastly barring any from entering its shadowed depths.
Over these long years, Ren watched silently as generations were born and faded away.
The cycle of life played out ceaselessly, while Ren held fast to his mission.
In the second year after Yoriichi's death, word came from Lord Muzan.
Lord Muzan expressed high praise for all Ren had accomplished.
For decades, while Muzan lay hidden, Ren had diligently managed the affairs of the Twelve Kizuki.
Though he never found a fitting Upper Rank, the Lower Rank members Ren carefully selected meticulously selected built a solid foundation for the Kizuki Corps.
Now, with Muzan's reemergence, Ren emerged was freed from the task of seeking new recruits for the Twelve Kizuki.
His mission complete, Ren chose to seal himself within these mountains.
In that lonely grave slept not only Chitoshi and Yoriichi but, in a sense, Ren himself.
Yet, while Ren remained in the valley, the outside world stirred with change.
The Twelve Kizuki welcomed many new members. Muzan, taking the reins, tirelessly sought powerful demons to complete the Kizuki ranks, sparing no effort over the decades.
More than once, Muzan urged Ren to leave his forsaken mountain, to aid in the search for exceptional talent, but Ren gently declined each time.
For any other demon, such defiance would have provoked Muzan's wrath, a lesson in why flowers bloom so red.
But this was Ren. Even Muzan hesitated to force him into tasks he loathed.
Perhaps it was because, during those hidden years, Muzan had seen Ren's deeds through the eyes of other demons.
Storming the Demon Slayer Corps' stronghold, severing Ubuyashiki's head—Ren had achieved what Muzan had dreamed of for centuries, a feat far more satisfying than Kokushibo's ambush on the Corps.
Thus, Muzan indulged Ren's whims unconditionally, not out of love but out of rare esteem for talent.
So Muzan acquiesced to Ren's seclusion. While even Kokushibo was ordered to scour the land for demon-worthy souls, Ren remained on his mountain, detached from worldly affairs, as if cut off from the world.
But this day, an unwitting demon dared to tread upon Ren's domain!
The moment that demon stepped into the mountain range, Ren, deep in the valley, opened his eyes.
At the same instant, the feeble demon glimpsed a monstrous, bloodshot pupil glaring coldly from the valley's depths.
Terrified, the demon dropped to his knees, cold sweat pouring. "By Lord Muzan's command, I bring a message for Lord Burial Crow!"
He held a letter aloft, kneeling, not daring to lift his head.
A crow landed before him, swallowing the letter whole.
At the same moment, a letter appeared in Ren's hand in the valley's depths.
He opened it, reading its contents.
The Twelve Kizuki were complete. Lord Muzan had called an Upper Rank meeting and sent this letter to invite Ren to attend.
Muzan could have summoned Ren directly, but this formal gesture showed respect, ensuring Ren would not refuse.
Ren pondered briefly. He had lingered here long enough. It was time to descend the mountain.
The crow sent the messenger demon away. Ren walked alone to Chitoshi and Yoriichi's graves.
Though centuries had passed, their tombstones stood as pristine as ever.
He reached out, tracing Chitoshi's stone. Time had eroded his memories of his human life, leaving them faint and fragmented.
Yet, though he could scarcely recall, gazing at the tombstone softened his heart, calming his restless spirit.
He stood before the graves for a long while, then turned and walked down the mountain.
Halfway down, he came upon a cluster of houses.
Before these homes, people went about their tasks—some chopping wood, others washing clothes—perhaps four or five households in all.
Amid their play, a child chasing friends stumbled into Ren.
Ren looked down at the boy.
Rubbing his head, the child pouted and slowly looked up. Seeing Ren's face, he froze.
The adults nearby, spotting this, dropped their tasks in panic and rushed to Ren.
"Forgive us, my lord! The child is young and didn't mean to disturb you," an elderly man said, kneeling in fear.
Ren crouched, ruffling the boy's hair. "Does it hurt?"
The boy stood timidly, too scared to speak.
The onlookers watched tensely, barely daring to breathe.
"There, there. A little rub, and it won't hurt," Ren said with a smile. The boy's face stirred a vague memory, though he couldn't place it.
He stood, addressing the kneeling elder. "Rise."
Then he announced something momentous: "I'm leaving. I may not return. You needn't guard this place anymore. If you wish to leave, go."
He had never commanded these people to guard the mountain. A century ago, those brothers, grateful for his rescue, vowed to protect it. After their deaths, their descendants carried on the duty.
But what need had this mountain for their protection? They were mere mortals.
In truth, Ren's presence had kept demons at bay and tamed the valley's fierce beasts, making them docile.
If anything, it was unclear who had protected whom these many years.
"You jest, my lord," the elder said with a sigh. "Our ancestors' words bind us. They swore to guard this place for generations. We cannot let that end with us."
"As you wish."
Ren didn't grasp their resolve, but if they chose to stay, he wouldn't force them to leave.
Besides, though he was departing, his demonic aura would linger in the mountain for decades, warding off intruding demons.
The villagers watched Ren's retreating figure. Suddenly, the elder knelt toward him. "We bid you farewell, my lord!"
The adults followed, kneeling. The children, tugged down by their parents, peered curiously at the fading silhouette.
Their elders often spoke of a deity dwelling in the mountains. Now, they had seen that deity for the first time.
Ren didn't pause. As he stepped beyond the mountain range, gazing at this world both strange and familiar, he closed his eyes. Ren had been forgotten. Henceforth, only Burial Crow would stride this earth.