What was cognition?
Cognition was the process by which humans acquired, processed, and applied information through mental activities such as perception, memory, and thought. It encompassed the ability to understand and adapt to the objective world.
In short, it was a complete system formed from everything one saw, heard, thought, experienced, and imagined.
In his previous life, Roy had watched Demon Slayer and put himself in the characters' shoes. He had experienced their joy, their sorrow, their grievances, and their anger. That was why they had left such a deep imprint on his Cognitive World.
Lost in thought, he sat up from the snow. A small cloth pouch fell from his chest, and a few pieces of candy rolled out. Only then did he remember that today was the full-moon celebration for his youngest sister, Delia Kamado.
Because of his intervention, Tanjiro was no longer the eldest son in the family. Rokuta, who was the youngest child in the original story, had not even been born yet. In other words... the story wouldn't begin for another two or three years...
Not only was his father, Tanjuro Kamado, still alive, but so was his grandmother—the white-haired old woman who often held Tanjiro in her arms as they watched the stars...
It was quite strange... In reality, Roy was the eldest son of the Zoldyck family, and in his Cognitive World, he was still the eldest son of the Kamado family. Perhaps it was precisely this "compatibility" that had allowed him to open the door to Demon Slayer.
Roy vaguely sensed the connection. He bent down, picked up the candies one by one, and then began checking his physical condition.
First, there was Nen...
Roy tried to connect with the aura inside his body, directing it toward the index finger of his right hand. A milky-white glow wavered. It was faint and barely noticeable against the snow, but it was undeniably there...
He couldn't help but breathe a sigh of relief.
After all, this world was no safer than the world of Hunter x Hunter. It was a world overrun by man-eating demons. Whether he had Nen or not was crucial, especially before he had mastered a Breathing Style and obtained a Nichirin Sword.
Then there were the "assassination techniques."
"Shadow Step," "Rhythm Echo," and "Snake Awakening"...
"Shadow Step": a stealthy assassination footwork passed down through generations of the Zoldyck family, centered on four principles: "light," "drifting," "unpredictable," and "illusory."
In motion, one was light as a swallow; in its strangeness, it was like a dream... Roy stepped forward, moving as lightly as a ghost. At times he went east, at times west, his figure weaving through the old forest. He was impossible to track, yet he didn't leave a single footprint in the snow. This... left a certain younger brother, worried about his big brother's safety in the dark, completely dumbfounded.
Today was Delia's full-moon celebration. Their father, Tanjuro, had sent their eldest brother, Eiichiro, down the mountain to buy supplies early that morning, but as evening drew near, he still hadn't returned... So Kie, the mother of Eiichiro and Tanjiro, sent Tanjiro, whose nose was as keen as a dog's, to look for him.
She hadn't expected that although Tanjiro found Eiichiro, he'd be left stunned himself.
The innocent, somewhat straightforward younger brother was wrapped in a thick black-and-green checkered coat, with a pale-purple scarf around his neck. He stood dumbly amid the swirling snow, his beautiful amber eyes reflecting Roy's ghostly, fluttering figure. His little mouth hung wide open, and the cry of "Big brother!" caught in his throat!
One thought kept repeating in his mind—was this... really his big brother Eiichiro?
It was... one hundred percent his big brother Eiichiro!
Eyes could deceive, but scent couldn't... Tanjiro's nostrils twitched. He confirmed that this was definitely Roy's scent, then quietly crept behind a large tree and poked his head out.
Roy had just practiced Shadow Step and familiarized himself with his body. Without taking a break, he began practicing "Rhythm Echo."
In essence, this "assassination technique" was an advanced application of Shadow Step.
Compared with Shadow Step, it added an extra layer of deception to confuse one's opponent.
Roy took a deep breath and stepped forward again. From where he stood, a circle of afterimages instantly spread outward.
Killua had used this move against Netero on the airship during the Hunter Exam, while competing with Gon to snatch the ball. But his opponent had been on an entirely different level; he'd been no match for someone like that, especially as a rookie who couldn't even use a Nen Ability.
But that had been Netero, the Strongest Human—not Tanjiro, who was still wet behind the ears...
Tanjiro's eyes widened all over again when he saw this... He stupidly counted off on his fingers, trying to figure out how many big brothers there were... But then a sharp, high-pitched "Zzt!" rang out—
A sharp hand blade shot past his ear and plunged into the tree he'd been using as cover!
"Snake Awakening": forging the hand into a blade, able to pierce anything. Once mastered to a subtle level, it could pierce rock; at its peak, it could pierce hardened steel; at perfection, it could cut through a Nen Artifact...
Roy had personally seen Silva sever a fine katana with a single hand blade!
But he was still only at the beginner stage. Being able to sink his hand three inches into a tree was already his limit. Anything beyond that would take time and practice... Unlike Bloodlust Perception, which he had picked up to some extent simply by being exposed to it!
That's right—Roy had noticed Tanjiro the moment Tanjiro found him!
He pulled his hand out of the tree he'd pierced and smiled at his familiar yet newly met younger brother. "Mother sent you to look for 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. Roy was clearly still breathing, but it was as if his soul hadn't returned to his body. He nodded dumbly, then hurriedly shook his head like a rattle-drum.
Seeing him like that, Roy couldn't help smiling as he patted his head. "Do you have a lot of questions you want to ask?"
Tanjiro shook his head, then nodded.
Roy's smile grew even warmer...
He said gently, "Today is Delia's full-moon celebration. Let's celebrate with her first, then talk afterward, all right?"
Tanjiro nodded vigorously.
Roy patted his shoulder and said no more. He flicked up the hoe with his toe and caught it in his hand, then bent down, hoisted the basket onto his back, and strolled home.
Tanjiro followed close behind, his head buzzing, until the moon rose above the treetops and stretched their shadows long...
Only then did he stop as well...
Through the snow and wind, they could now make out several familiar wooden cabins in the distance.
Thin streams of smoke rose from the one facing east. The laughter of children and the coughs of adults could be heard faintly. Add a few barks and cats darting about, and it would have made a perfectly heartwarming picture of village life.
"Too bad... demons really do exist in this world... and in two or three years, this place will be gone, too..."
Roy murmured softly.
Tanjiro looked up at him in confusion. "Demons?"
Clearly, his big brother didn't want to explain any further. By the time Tanjiro looked again, Roy had started walking toward home.
Tanjiro hesitated, tightened the scarf around his neck, and hurried after him.
Hearing the commotion, the adults and children inside poked their heads out... When they saw Roy and Tanjiro, the children cheered excitedly...
There were Nezuko, Takeo, Shigeru, and the youngest, Delia, still swaddled in the arms of a white-haired old woman...
"Big brother Eiichiro, you're back!"
"Mm... I'm back..."
Roy replied with a smile, meeting the gaze of the man sitting at one end of the veranda.
The man coughed a few times as he fiddled with a set of traditional Japanese ceremonial robes. When he saw Roy looking his way, he smiled warmly too...
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