The Journey and High-Speed Movement with "Blue"

Moyu returned to the Butterfly Mansion and packed a few changes of clothes and some emergency medicine. After carefully checking his Nichirin Blade, Azure Star, he fastened it at his waist.

He went over to Tanjiro and Zenitsu, who were sparring in the courtyard.

"Tanjiro, Zenitsu, Inosuke." Moyu's voice brought all three to a halt.

"Moyu? What is it?" Tanjiro asked, wiping away his sweat.

"I'll take the Mugen Train mission. The three of you have other assignments." Moyu kept it brief.

"Huh?! You're going, Moyu?" Zenitsu was stunned for a moment, then delighted. "That's great! We don't have to go somewhere so dangerous!" But his face quickly fell. "Wait... our new mission won't be really hard too, will it?"

"I'll ask Shinobu Kocho to choose suitable missions for you, mainly so you can get used to using Total Concentration: Constant and Haki." Moyu looked at Tanjiro. "Tanjiro, keep an eye on those two. Make sure Zenitsu doesn't slack off, and don't let Inosuke do anything reckless."

"Yes! You can count on me, Moyu!" Tanjiro straightened up, his gaze serious. "I'll make sure they train hard!"

"Hmph! Who needs you watching me?" Inosuke snorted in displeasure, but didn't argue.

Moyu went over to the veranda, where Nezuko's box had been placed. He gently knocked on the lid.

The box opened a crack, and Nezuko's small head peeked out. When she saw Moyu, she blinked her large eyes and made a cheerful "mm-mm" sound.

"I'm leaving on a mission, Nezuko." Moyu's voice was a touch softer than usual. "Behave yourself at the Butterfly Mansion, and don't go running off."

"Mm!" Nezuko nodded vigorously, then reached out a little hand and tugged gently at Moyu's sleeve, as if telling him to be careful.

Moyu raised his hand and hesitated for a moment, then gently patted Nezuko on the head. Her hair was soft.

Finally, he went to Shinobu Kocho, who was sorting medicinal herbs in the pharmacy. She seemed to have known he was coming; before he could speak, she turned around with her trademark gentle smile, though a trace of barely perceptible worry lay hidden deep in her purple eyes.

"Are you leaving?"

"Yes." Moyu nodded.

Shinobu Kocho stepped forward and gently straightened his collar and the folds of his haori. "Remember... come back alive."

Moyu looked into her purple eyes, so close to his own, and a remarkably faint smile appeared on his usually calm face.

"I will."

With that, he stayed no longer. He turned, waved, and stepped through the gates of the Butterfly Mansion. The sunlight stretched his tall figure into a long shadow.

Once he was clear of the Butterfly Mansion, Moyu picked up his pace. At first he traveled normally, but his mind kept returning to the applications of "Blue" from before he transmigrated—Satoru Gojo's "Short-Range Teleportation" technique, which was almost like teleportation.

The principle wasn't complicated. At its core, "Blue" manipulated gravity, creating a powerful "attraction" directed toward the user. If he could precisely control the direction, strength, and range of that attraction, he could theoretically "pull" himself instantly toward a target point, achieving extremely high-speed movement.

Before, his physique and total Cursed Energy (I'll stick with Cursed Energy; it's easier to write) had been limited, so he hadn't dared attempt such a delicate and enormously costly maneuver. But now...

Moyu stopped, his azure eyes narrowing slightly. With his Six Eyes fully active, information about the space around him flooded in like a tide. He locked onto a tree roughly fifty meters ahead.

With a thought.

Hum—

An invisible, powerful gravitational force instantly arose at the tree's position, reaching out to "grab" Moyu with clear intent. At the same time, Moyu pushed off with his feet.

Whoosh!

His figure abruptly blurred, and almost in the same instant, he appeared beside the tree fifty meters away! He had moved so fast that he left only an afterimage, and the rapidly compressed air gave a soft crack like a sonic boom.

"It worked." Moyu assessed the energy he had used. Between the Sage Body's powerful regenerative ability and the efficient energy circulation granted by Total Concentration: Constant, the expenditure was almost negligible. The movement had also been smooth, placing very little strain on his body.

"Not bad," he murmured, a trace of satisfaction flashing in his eyes.

For the rest of the journey, Moyu abandoned conventional travel entirely. Like a ghost moving through the mountains and forests, every activation of "Blue" instantly "projected" his body hundreds or even thousands of meters ahead. Mountains, rivers, and dense forests raced past beneath him. He was far faster than a fine horse, and even much faster than a Kasugai Crow flying at full speed to deliver a message for the Demon Slayer Corps.

A journey to the Mugen Train mission area that might originally have taken two or three days brought Moyu to the outskirts of a nearby town by sunset that same evening.

Standing on a small hillside, overlooking the town below as lights gradually came on, Moyu recalled the plot. Before the Mugen Train incident, a Demon known for its speed seemed to have been active nearby, frequently attacking lone pedestrians at night.

He needed to deal with this unpredictable factor first.

It wasn't difficult to contact a member of the Kakushi investigating nearby. Using a special method of communication, Moyu soon found a member responsible for gathering intelligence, a nervous-looking young man.

"E-Eye Hashira, sir!" The young man was excited and awed to see Moyu. "You got here so quickly?"

"Yes. Is there a very fast Demon active nearby? Tell me what you know." Moyu got straight to the point.

"Yes, sir! Based on scattered survivors' accounts and the locations of the disappearances, we've determined that a Demon is indeed roaming the western and northern parts of town, specifically targeting people walking alone at night. It moves extremely fast. Victims often disappear before they can even call for help. The people we sent after it have lost its trail several times. It's very alert and incredibly fast." The young man delivered his report quickly.

"Where does it usually operate?" Moyu asked.

The young man pointed out several areas on a map.

"I understand. Go back to monitoring the train maintenance depot." Moyu committed the locations to memory, then his figure flickered and vanished into the gathering dusk.

In the western district of town, deep in a secluded alley.

A girl in a kimono, her hair arranged in a pretty bun, hurried home with the snacks she had bought. It was already dark, and there were no streetlights in the alley, only the faint sounds of the bustling main street in the distance. She was a little frightened and couldn't help quickening her pace.

Suddenly, a cold wind blew in from the mouth of the alley. The girl shivered and instinctively looked back.

A figure had appeared at the entrance to the alley, blocking her way. It was a tall, thin man dressed in black, his face unnaturally pale and his mouth stretched into an exaggerated grin that exposed sharp teeth. His eyes were an eerie blood-red, glowing faintly in the dark.

"Good evening, little girl." The Demon's voice was hoarse and excited. "It's dangerous to walk alone at night..."

The girl's pupils contracted. Terror made it almost impossible to breathe, and though she wanted to scream, it was as if a hand had closed around her throat.

The Demon approached at a leisurely pace, savoring his prey's fear. "Don't be afraid. It'll be quick... Your flesh and blood smell delicious..." He extended his long tongue and licked his lips.

Just as the Demon's claws were about to touch the girl's shoulder—

Hum!

The air gave an almost imperceptible tremor.

A tall figure appeared without warning between the girl and the Demon, as if tearing through space! He had moved so fast that it seemed he had been standing there all along, without even leaving an afterimage.

The Demon's sinister grin froze, and his blood-red eyes filled with incredulous shock. He hadn't sensed anyone approaching at all! How had this man appeared?!

Moyu's gaze was icy. He didn't even draw his blade. He simply raised a foot, seemingly at random, and drove a side kick into the Demon's abdomen at a speed the naked eye could barely follow!

"Bang!!!"

A dull impact rang out, accompanied by the unmistakable crack of breaking bones. As if struck head-on by a train traveling at full speed, the Demon became a black blur and flew backward like a cannonball! He smashed through the earthen wall on the other side of the alley, sending dust flying.

The girl collapsed to the ground, staring blankly at the back of the figure standing before her. A black uniform, a white haori, and the azure tips of his hair, conspicuous even in the dim light, as if they reflected a starry sky.

"Stay where you are. Don't move." Moyu didn't turn around. His voice was calm and matter-of-fact, yet carried an unquestionable force.

"Urgh..." The Demon struggled to his feet amid the rubble. His abdomen was visibly caved in, and intense pain twisted his face. But he was even more shocked by his opponent's speed and strength. "You... who are you?!"

Moyu didn't answer. He simply drew Azure Star slowly from his waist. The blade gleamed coldly in the moonlight, like flowing water.

Intense fear and a trace of cunning flashed in the Demon's eyes. I can't beat him! The difference in speed is too great! I have to escape! He spun around, dropped to all fours, and unleashed his full speed, darting deeper into the alley like a bolt of black lightning! This was the ability he relied on to survive—extreme speed!

In the blink of an eye, he had covered nearly a hundred meters. He glanced back and saw that the terrifying human hadn't immediately pursued him.

Hmph! No matter how fast he is, there's no way he can catch me when I'm running for my life at full speed! The Demon felt somewhat reassured and planned to escape the town first, then find food somewhere else. He had been truly unlucky this time, running into such a tough opponent.

Yet when he turned his head back to check his direction, the blood in his body almost froze in an instant.

The figure in the black uniform, a long blade in hand, was standing silently in the middle of the road less than ten meters ahead of him, having appeared there like a ghost! Moonlight fell on him, and his azure eyes were calm and undisturbed, as if he had been waiting there for a long time.

"When... did you..." The Demon's pupils shrank to pinpoints, his teeth chattering as boundless terror engulfed him. How is that possible?! When did he?! How did he get here?! I was already running away at full speed!

"Is that all the speed you have?" Moyu finally spoke, his voice betraying no emotion.

Scared out of his wits, the Demon turned to flee in another direction, but fear made him falter for an instant.

That instant was all it took.

Moyu took a deep breath, then shot forward like an arrow loosed from a bow, azure currents of air swirling around him.

He hadn't used "Blue" to move. This was purely his own explosive power at its peak, bolstered by his Breathing Style and Sage Body!

Slash!

A flash of deep blue blade light traced a graceful arc through the night, moving faster than the Demon's eyes could follow.

The Demon felt only a chill at his neck before his vision began to spin. The last things he saw were his own headless body slowly falling, and the cold figure sheathing his blade, then turning and walking away.

"So... fast..."

That was his only thought before his consciousness faded.

[Upper-Rank Demon killed ×1. Coins obtained: 4,000]

The system notification sounded.

Moyu walked back to the alley. The girl was still sitting on the ground, her face pale, though she had recovered somewhat.

"The Demon is dead. Don't walk alone on deserted roads at night again." After saying that, Moyu didn't linger. His figure flickered, and he vanished at the mouth of the alley.

The girl looked at the empty alley, then at the Demon's corpse slowly turning to ash amid the rubble in the distance. After a long while, she shakily got to her feet and bowed deeply in the direction Moyu had disappeared.

Over the next two days, Moyu searched carefully around the station where the Mugen Train was expected to stop, scanning every corner with his Six Eyes, but he found no trace of any other Demons. Enmu either had yet to possess the train or was hidden extremely well.

Through the Kakushi's intelligence, he learned that the Mugen Train was undergoing maintenance at the depot because of what had happened a few days earlier, and it would be several more days before it returned to service.

"There's still enough time." Moyu found an inconspicuous inn near the station and checked in. He needed to wait for the train to depart, and he also needed some time to further familiarize himself with and develop the use of "Blue" in movement and combat.

He stood at the window of his room, gazing at the faint outline of the train maintenance depot in the distance, his azure eyes glowing faintly in the darkness.