Practicing Assassination Arts, Brothers Meet for the First Time

What is cognition?

Cognition is the process by which humans acquire, process, and apply information through psychological activities such as perception, memory, and thinking, encompassing the ability to understand and adapt to the objective world.

In summary: it is a complete system formed by everything one has seen, heard, thought, and experienced.

In his previous life, Roy had watched Demon Slayer and immersed himself in its characters, experiencing their joys, sorrows, grievances, and rage; it was for this reason that he had left a deep footprint in the world of his own cognition.

Lost in thought, he rolled over and sat up from the snow. A small cloth bag fell from his chest, spilling a few candies, which reminded him that today was the full-month celebration for his youngest sister, Hanako Kamado.

Due to his intervention, Tanjiro was no longer the eldest son of the family, and Rokuta, the youngest child in the original work, had not yet been born. This meant... there were still two or three years left before the plot began.

Not only was his father, Tanjuro Kamado, still alive, but even his grandmother—the white-haired old woman who often held Tanjiro while they watched the stars—was still among the living.

This was quite marvelous... In reality, Roy was the eldest son of the Zoldyck family, and in his cognitive world, he remained the eldest son of the Kamado family. Perhaps it was this "compatibility" that allowed him to push open the door to [Demon Slayer].

Roy vaguely sensed the connection. He bent down to pick up the candies one by one, then immediately began to check his physical state.

First was "Nen"...

Roy attempted to communicate with the aura within his body, mobilizing it to surge toward his right index finger. A milky-white halo flickered; though faint and not particularly conspicuous against the backdrop of the white snow, it existed nonetheless.

This made him heave a sigh of relief.

After all, this place was no kinder than the world of Hunter x Hunter; it was a world rampant with man-eating demons. Having "Nen" or not was of vital importance before he had mastered Breathing Styles or obtained a Nichirin Sword.

Next, was "Assassination Arts."

"Shadow Step," "Rhythm Echo," and "Snake Awakening"...

"Shadow Step": An assassination footwork passed down through generations of the Zoldyck family, focusing on the four elements of "lightness," "drift," "stealth," and "illusion."

When in motion, one is as light as a swallow and as elusive as a dream... Roy took a step, moving as lightly as a ghost. He darted east and west, his figure weaving through the old forest. While his trail was impossible to track, he did not leave a single footprint in the snow. This... left a certain younger brother, who had been worried about his big brother's safety in the dark, completely stunned.

Today was Hanako's full-month celebration, and his father, Tanjuro, had instructed his eldest son, Eiichiro, to go down the mountain to shop early in the morning. As evening approached and he still hadn't returned... Kie, the mother of Eiichiro and Tanjiro, had sent Tanjiro, who possessed a dog-like nose, to find him.

He hadn't expected to find Tanjiro, but the boy himself had been struck dumb.

The innocent and somewhat straightforward younger brother was wrapped in a thick black-and-green checkered coat with a pale purple scarf around his neck. He stood blankly in the heavy, swirling snow, his beautiful amber eyes reflecting Roy's ghostly, fluttering figure. His small mouth was wide open, and the word "Onii-chan" was stuck firmly in his throat!

His heart kept repeating one thought—was this... really his big brother Eiichiro?

It was... one hundred percent his big brother Eiichiro!

Eyes could be deceived, but scents could not... Tanjiro's nostrils twitched. Confirming that this was indeed Roy's scent, he quietly crept behind a large tree, poking only his head out.

Having just practiced Shadow Step and re-familiarized himself with his body, Roy did not rest and immediately began to practice "Rhythm Echo."

This "assassination technique" was, in essence, an advanced application of "Shadow Step."

Compared to "Shadow Step," it added a layer of effects to confuse the opponent.

Roy took a deep breath and stepped out again, instantly pulling a circle of afterimages from his starting point.

This move was something Killua had used against Netero while competing with Gon for the ball on the airship during the Hunter Exam, though the opponent's level was too high for a rookie who couldn't even use Nen to challenge.

But that was the strongest human, Netero, not the fledgling Tanjiro...

When Tanjiro saw this, his eyes widened again... He foolishly counted on his fingers, subconsciously trying to figure out how many big brothers there were... but before he could, a sharp "shing!" sound rang out—

A sharp hand-blade had pierced the very tree he was hiding behind, right beside his ear!

"Snake Awakening": Forging the hand into a blade, unbreakable. Once reaching the level of subtlety, it could pierce through mountain rock; at great success, it could pierce refined iron; at perfection, it could sever Nen-imbued tools...

Roy had seen Silva sever a high-quality samurai sword with a single hand-blade with his own eyes!

However, he was still in the rudimentary stage; being able to pierce wood was his limit. Anything more would require time to hone... unlike Bloodlust Perception, which one could pick up a bit of through constant exposure!

That's right, the moment Tanjiro found Roy, Roy had also discovered Tanjiro!

He pulled his hand out of the tree he had just pierced and looked at this younger brother—familiar yet newly met—with a smile: "Mother sent you to find me, didn't she... Sorry, I fell asleep just now and made you all worry."

Tanjiro looked at Roy's face, then glanced at his right hand. He was clearly still breathing, but his soul hadn't quite returned to his body. He nodded blankly, then hurriedly shook his head like a rattle-drum.

Seeing him like this, Roy amusedly patted his head: "Are there many questions you want to ask?"

Tanjiro shook his head, then nodded.

Roy's smile deepened...

He said gently: "Today is Hanako's full-month celebration. Let us celebrate for Hanako first, and we can talk later, alright?"

Tanjiro nodded vigorously.

Roy patted his shoulder, said nothing more, flicked his toe to catch the hoe, bent down to shoulder his basket, and strolled toward home.

Tanjiro followed him step by step, his head buzzing, until the moon climbed to the treetops, stretching their shadows long...

Only then did he stop his pace...

From this distance, through the wind and snow, the familiar little wooden huts could already be seen.

The one to the east had wisps of cooking smoke rising from it, and one could faintly hear the laughter of children and the coughing of adults. If one added the barking of dogs and the jumping of cats, it would surely weave a warm, idyllic village scene.

"It's just a pity... that demons truly exist in this world... and in two or three years, this place will no longer exist..."

Roy whispered softly.

Tanjiro looked up at him in confusion: "Demons?"

Clearly, his eldest brother did not wish to offer further explanation; with another glance, he had already resumed his stride, heading toward their home.

Tanjiro stood stunned for a moment, then tightened the scarf around his neck and hurried to catch up.

At that moment, hearing the commotion, the adults and children inside the house poked their heads out... seeing that it was Roy and Tanjiro, several of the children cheered with joy.

There was Nezuko, Takeo, Shigeru, and the youngest, still in swaddling clothes and held in the arms of a white-haired old woman, Hanako...

"Big Brother Eiichiro, you're back!"

"Mm... I'm back..."

Roy responded with a smile, his gaze meeting that of the man sitting in the corner of the veranda.

The man coughed a few times, his hands busy fiddling with a set of traditional Japanese ceremonial robes; seeing him look over, he offered a gentle smile in return...