In the gloomy bamboo forest, the moonlight was sliced into mottled, fragmented shadows.
The Serpent Hashira, Iguro Obanai, was sprinting along the path. The white snake coiled around his neck, Kaburamaru, flicked its tongue continuously, sensing their surroundings.
Suddenly, his footsteps halted.
Kaburamaru hissed uneasily beside his neck, transmitting a signal of extreme danger.
Up ahead, a figure leaned silently against a bamboo stalk, looking as if he had always been a part of this forest.
The man's face was so pale it lacked even a trace of blood. A pair of golden, slitted pupils flickered with an eerie light in the shadows. Just being stared at by those eyes sent a chill straight to Obanai's bones.
"Your method of training seems quite interesting," the man spoke, his voice hoarse with a viscous quality. He stuck out an unnaturally long tongue and licked his lips. "Adapting human sword techniques to mimic the movements of a snake. What a wonderful idea."
Obanai's muscles tensed completely, his right hand already gripping the bandage-wrapped hilt of his Nichirin Sword.
'Danger!'
'Extreme danger!'
'This man in front of me isn't a demon, yet he is far more bizarre and evil than any demon I've ever seen!'
"Who are you?" Obanai asked, his voice ice-cold.
"Me?" The man chuckled low, the sound echoing through the bamboo forest and making Kaburamaru even more agitated. "You may call me Orochimaru."
Orochimaru stepped slowly out of the shadows, his serpentine eyes appraising Obanai with great interest.
"I can feel your thirst for power."
"You want to become stronger—strong enough to protect the one you wish to protect, correct?"
Obanai's heart jolted violently, his fingers tightening involuntarily around his sword.
"I can give you that opportunity," Orochimaru said, his voice brimming with temptation. "I can teach you true 'jutsu'."
Obanai instinctively felt a strong sense of repulsion.
Every single word from this man exuded an aura of pure evil.
However... that thirst for power, that obsession to stand proudly beside Mitsuri Kanroji and protect her, was like a seed quietly planted in the depths of his heart, taking root and sprouting uncontrollably.
...
Butterfly Mansion.
"Water Breathing, Tenth Form: Constant Flux!"
Tanjiro Kamado was sweating profusely as the Nichirin Sword in his hands conjured an endless water dragon that coiled and danced through the courtyard.
He was training hard, simultaneously reviewing and deducing the vague movements of the Hinokami Kagura in his mind.
Right at that moment.
Boom!
An indescribably terrifying and scorching aura of oppression suddenly descended!
Aoi Kanzaki, who was airing out futons in the yard, and Kanao Tsuyuri, who was feeding the butterflies, both stiffened violently, instantly paralyzed.
The air grew thick and heavy, making even drawing a breath feel like an extravagant hope.
It felt as though the most scorching midday sun had suddenly plummeted from the heavens and smashed right into this tiny courtyard!
Tanjiro's movements came to an abrupt halt, and he turned his head with great difficulty.
He saw a man with an exaggeratedly burly physique standing in the center of the courtyard, having appeared out of nowhere.
He sported a handlebar mustache and bulging, knotted muscles, radiating an unrivaled, domineering pressure that seemed to rule over the world.
Just by standing there, the man stole all the luster from his surroundings.
It was as if he were the sun itself!
He was the center of the world!
The man cast a disdainful glance at the stiffened Tanjiro, his eyes looking down upon all creation.
"Oh? So you are the brat who has grasped a fraction of the sun's power? How laughably feeble."
He proudly puffed out his chest and declared in a booming voice:
"Listen well, boy! I am the Lion's Sin of Pride from the Seven Deadly Sins—Escanor!"
"I have come at the behest of an 'interesting person' to offer some guidance to that pathetic 'sun' of yours, which is no brighter than a firefly!"
Just from those few words, the overwhelmingly tyrannical presence nearly forced Tanjiro to his knees, draining away even the strength to hold his sword.
'Is this... the oppressive weight of the sun?'
...
"Gyaaaah! I don't want to train anymore! I'm going to die! I'm really going to die!"
Zenitsu Agatsuma was crying so hard that snot and tears streamed down his face. He scrambled and crawled away from the grueling basic training, letting out shrieks like a slaughtered pig.
Just a moment before he could dash out the gates of the training grounds.
Swish!
A golden flash of light instantly appeared right in front of him.
Zenitsu slammed headfirst into a gentle yet solid chest, bouncing right back and landing hard on his rear.
"Eh?"
He lifted his tear-stained face and stared blankly at the person before him.
It was a young man with brilliant blond hair and blue eyes as clear as the sky.
He wore a white haori with the words "Fourth Hokage" written on the back, and a warm, gentle smile like the sun hung on his face.
"You run very fast, but not quite fast enough," the man said gently, his voice as soothing as a spring breeze.
He effortlessly pinned down the shoulder of the fleeing Zenitsu, rendering him completely immobile.
"I saw your 'Thunder Breathing, First Form'."
"To erupt with speed surpassing your limits in a single, ultimate instant—it holds astonishing potential."
The man's smile was full of encouragement and validation.
"My name is Minato Namikaze."
"Starting today, I will teach you how to become the 'Yellow Flash'!"
Zenitsu froze.
'Yellow... Flash?'
...
Meanwhile.
Infinity Castle.
Twisted, upside-down architecture stretched across the endless space, exuding an eerie and ominous atmosphere.
Muzan Kibutsuji stood at a high vantage point, a clear image reflecting in his crimson eyes.
It was a "memory" he had acquired from his alternate self in another world.
A courtyard blooming with blue flowers.
The Blue Spider Lily!
A thousand years!
His ultimate dream, which he had pursued for a millennium, was right before his eyes!
"Nakime," he spoke coldly.
With the strum of a biwa, a haggard-looking demon was teleported before him.
"Go, bring this back," Muzan ordered, his voice devoid of emotion as he directly transmitted the image from his mind into the demon's head. "Remember, do not let anyone discover you."
This demon was one he had specifically chosen.
Its Blood Demon Art was called "Puppet Thread," which allowed it to control humans from a distance, turning them into marionettes at its mercy.
For this mission, it couldn't be more perfect.
"Y-Yes! Lord Muzan!"
After receiving the order, the demon immediately vanished from its spot.
...
The next day, at noon.
The sunlight was blinding, and the air was filled with the fragrance of vegetation.
A villager was braving the scorching sun, weeding his fields.
Suddenly, his movements paused.
His eyes instantly lost all their light, becoming completely hollow.
Like a puppet controlled by invisible strings, he walked step by step toward the top of the mountain.
There, blooming under the sunlight, was a sea of faint blue flowers.
The Blue Spider Lily.
Under the glaring sun, the gardener reached out and plucked every single Blue Spider Lily, leaving not a single one behind.
...
Infinity Castle.
When that bouquet of faintly glowing blue flowers was respectfully presented by the demon.
Muzan's body trembled slightly from extreme excitement.
This was it!
As long as he ate this, he would become an immortal, unaging ultimate lifeform that no longer feared the sun!
His thousand-year-old wish was about to be fulfilled!
However, the agonizing memory originating from the other world—of being burned to ashes by the sunlight—forced him to suppress the ecstasy in his heart.
A millennium of caution did not allow him to make any careless mistakes.
He turned expressionlessly toward the demon and ordered coldly, in a tone that brooked no argument:
"You. Eat it."
"Prove your worth to me, and prove... the worth of this flower."
The demon shuddered violently. Not daring to disobey, it could only tremble under Muzan's icy gaze as it picked up a blue flower and stuffed it into its mouth.