The temple stood silent atop Mount Kōya, its wooden beams groaning under the weight of centuries. Mist clung to the eaves, and the scent of incense lingered in the air, masking the underlying aroma of decay. Within its hallowed halls, monks moved like shadows, their chants a constant murmur that resonated with the mountain's heartbeat.
In the depths of this sanctum, beneath the main hall, a boy sat cross-legged on the cold stone floor. His name was Shinjuro Sanzō, and at the tender age of ten, he had already memorized the sutras of death. His hands, small yet calloused, held a blade not meant for combat but for ritual—a tanto used in the temple's esoteric ceremonies.
"Again," intoned the head monk, his voice devoid of emotion.
Shinjuro recited the verse, each word a blade slicing through the silence:
"From darkness we come, to darkness we return. The flesh is transient; the soul, a fleeting whisper."
The monk nodded, satisfied. "Now, the offering."
A small cage was placed before Shinjuro, containing a sparrow with feathers as white as snow. He opened the cage, gently cradled the bird, and with a swift motion, ended its life. He placed the lifeless body on the altar, lighting a stick of incense beside it.
The ritual was complete.
Years passed, and Shinjuro grew into a young man. His demeanor remained unchanged—stoic, detached, and eerily serene. The temple's teachings had molded him into a vessel of ritualistic precision, devoid of empathy.
One evening, as the sun dipped below the horizon, casting long shadows across the temple grounds, a stranger arrived. Clad in the uniform of the Demon Slayer Corps, the man introduced himself as Kaito, a recruiter seeking individuals with exceptional skills.
The head monk saw an opportunity. "Shinjuro," he said, "your path lies beyond these walls. Serve the Corps, and continue our sacred rites in the world beyond."
Shinjuro accepted without question.
The Demon Slayer Corps welcomed Shinjuro, impressed by his discipline and mastery of the blade. However, his methods unsettled many. He performed purification rituals before and after each mission, reciting verses over the corpses of demons and humans alike. His fellow slayers whispered of his cold demeanor and the unsettling calm with which he dispatched his foes.
During a mission in a remote village plagued by demon attacks, Shinjuro encountered a creature unlike any he had faced before. Towering and grotesque, the demon sneered, revealing rows of jagged teeth.
"Another lamb to the slaughter," it hissed.
Shinjuro remained unfazed. He drew his blade, its edge gleaming in the moonlight. As he engaged the demon, he recited a new verse:
"Blood sanctifies the blade; death completes the rite."
With a final, decisive strike, he severed the demon's head. As its body disintegrated, Shinjuro knelt, pressing his forehead to the ground in silent prayer.
The villagers, witnessing the act, were both grateful and terrified. They spoke of the slayer who treated death as a sacrament, whose eyes held no light.
Word of Shinjuro's methods reached the higher echelons of the Corps. Some viewed him as a necessary evil, a weapon to be wielded against the darkness. Others feared the darkness within him.
One night, Shinjuro was summoned by a senior member of the Corps. "Your next mission is of utmost importance," the man said. "A demon of considerable power has been spotted in the northern mountains. Few have faced it and lived."
Shinjuro bowed. "I shall perform the rites."
The journey to the mountains was arduous. Snow blanketed the landscape, muffling sound and obscuring paths. As Shinjuro ascended, he felt a presence—ancient and malevolent.
At the summit, he found a cavern, its entrance marked by clawed footprints and the stench of decay. Inside, the demon awaited—a being of immense size, its skin a tapestry of scars and eyes.
"You are not like the others," it growled. "Your soul is… empty."
Shinjuro stepped forward, blade drawn. "I am the vessel. You are the offering."
The battle was fierce. The demon's strength was unparalleled, but Shinjuro's precision and unyielding resolve allowed him to hold his ground. As the fight reached its climax, the demon lunged, claws poised to rend flesh.
In that moment, Shinjuro recited a final verse:
"From void to void, the cycle completes."
He drove his blade into the demon's heart, a burst of light illuminating the cavern. The creature let out a final, guttural scream before collapsing into ash.
Exhausted, Shinjuro knelt, his body trembling. He felt a warmth spreading through him—a sensation foreign and unsettling. Unbeknownst to him, the demon's blood had seeped into his wounds, mingling with his own.