Transported to Demon Slayer: Awakening of the Azure Eyes

Mist hung over the mountain path late at night.

Moyu pressed his back against a dead tree, both hands covering his nose and mouth. He kept his breathing to the faintest whisper. His heart pounded in his chest, each beat seeming loud enough for that thing to hear.

"I see you..."

The cloying voice came from the bushes thirty meters away. Moonlight shone through a break in the clouds, illuminating a pair of blood-red eyes.

A Demon.

Moyu's teeth chattered, not just from fear, but from an outrage so intense it was absurd. He was an ordinary twenty-first-century homebody who had stayed up late rewatching the Mugen Train arc of Demon Slayer: Kimetsu no Yaiba and grieving Kyojuro Rengoku's sacrifice. Then he had closed his eyes, opened them, and found himself lying in a Japanese mountain forest in some godforsaken era.

Being transported was one thing, but he didn't even have a cheat.

He had no Breathing Style inheritance, no Nichirin Blade, and even the original owner's memories were fragmented. All he knew was that the boy's name was Moyu, that he was an orphan who gathered herbs, and that he lived in a village at the foot of the mountain. Three days ago, he had gone up the mountain to gather herbs, and then...

Then he had encountered a man-eating Demon.

"You're fast, little guy." The thing sauntered out of the bushes. It looked like a stretched-out human, with sickly gray-white skin and nails a good half-foot long on all ten fingers, gleaming like metal in the moonlight. "But it's no use. Your scent... smells so good. Better than those farmers earlier."

Moyu's gaze swept over his surroundings. A steep slope lay to his left, dense forest to his right, and the way back was blocked. Ahead... the Demon was slowly closing in.

Calm down, calm down. He screamed at himself inwardly. You've watched all of Demon Slayer. You know Demons' weaknesses: sunlight, decapitation with a Nichirin Blade, and certain specially made Wisteria Poisons. But right now you don't have any of them.

No, that's not right. You still have your brain.

"Wait!" Moyu spoke suddenly, his voice hoarse with tension. "You... Muzan turned you into a Demon, didn't he? The man in the suit, the one who gave you blood."

The Demon stopped moving.

Confusion flickered in its blood-red eyes, followed by deeper malice. "You know that lord's name? Interesting... all the more reason to eat you, then. There might be something in your head that interests him, hehehe!!"

Damn it, that backfired. Moyu cursed inwardly as his body sprang to the left. The trees there were relatively sparse; perhaps he could use the terrain to hold out until dawn.

"Trying to run?"

The Demon's figure blurred. It wasn't a Blood Demon Art, just the natural physical abilities of a Demon, several times greater than a human's. Moyu's vision blurred, and a tearing pain ripped through his chest.

An immense force sent him flying, and his back slammed against a tree trunk. The dead tree's branches cracked under the strain.

"Cough...!" Blood sprayed from his mouth. Moyu looked down and saw three cuts across his chest, deep enough to reveal bone. If he hadn't twisted away at the last moment, those claws would have pierced straight through his heart.

Pain, unimaginable pain. It hurt a hundred times worse than any injury he had suffered in real life.

"You look delicious struggling, too." The Demon licked the blood from its nails, an intoxicated expression on its face. "But it's time to end the game. Dawn's almost here."

Moyu's consciousness began to fade. He had lost too much blood, his body was losing heat, and black spots had appeared at the edges of his vision.

Am I going to die?

Die at the hands of this nameless Demon, a meaningless death, just like those unnamed bystanders in the anime?

No.

I don't want to die.

Tanjiro is still waiting for his sister to become human again, Mr. Rengoku hasn't sacrificed himself yet, Kanao Tsuyuri hasn't opened her heart, Sister Shinobu Kocho hasn't...

There are still so many regrets.

So many endings he wanted to change.

[Strong fixation detected... binding conditions met...]

[Activating Myriad Worlds Exchange System...]

A cold mechanical voice sounded directly in his mind. Moyu's eyes snapped wide open. The voice hadn't come from outside; it had surged up from the depths of his consciousness.

[Activation complete. Host detected to be near death. Initiating emergency protocol.]

[Newbie gift package issued: Satoru Gojo's Six Eyes from the world of Jujutsu Kaisen (childhood stage/not fully unlocked)]

[Accept?]

Accept! Moyu roared in his mind.

[Fusion commencing. Warning: this ability places an immense burden on the host and may cause unpredictable side effects. Countdown: 3... 2... 1...]

The world changed.

The first thing to flood in was information: a vast, chaotic, raging torrent of it.

Moonlight was no longer simply light, but a collection of wavelengths, frequencies, and energy intensities. Air was no longer empty space, but a dance of countless molecules and atoms; he could "see" the trajectories of oxygen and nitrogen atoms. The cellular structures of trees, the microorganisms in the soil, the hydrogen bonds between water molecules in a distant stream...

Everything became transparent, analyzable data.

And that was only the background.

What truly made Moyu hold his breath was the "Demon" before him.

In the Six Eyes' field of vision, it was no longer a vague humanoid monster. He saw the flow of energy, clear and conspicuous as a lighthouse in the dark. Black, turbid energy radiated from the Demon's heart and flowed throughout its body along strange pathways. At one of the nodes in those pathways, particularly at the neck, was an extraordinarily complex knot of energy, a "core" that looked like countless threads of death tangled together.

Death Point.

The term came naturally to Moyu's mind. It was something more fundamental than a Breathing Style's Demon Slayer Mark: the life core of a being like a Demon.

"Hm?" The Demon tilted its head, evidently noticing the change in Moyu. His eyes, once filled with fear, now shimmered with a strange azure light, as though they held the entire starry sky. "Your eyes..."

Before it finished speaking, Moyu moved.

It wasn't thought that guided him, but instinct granted by the Six Eyes. He "saw" the signs of the Demon's muscles contracting, saw the path of energy gathering in its legs. The moment the Demon pushed off the ground and lunged forward, Moyu had already rolled to the right.

The claw strike missed, tearing into the trunk he had been leaning against.

"How is that possible?!" Doubt and alarm entered the Demon's voice for the first time.

Moyu didn't answer. His brain was working beyond its limits, processing every piece of information from the Six Eyes. The Demon was fast, but under the Six Eyes' dynamic vision, every movement was broken down into countless frames, every attack trajectory calculated in advance.

He dodged the second strike. The third. The fourth.

Every time, he escaped by a hair's breadth. Every time, it was like dancing on a blade's edge. The wounds on his chest were still bleeding, and his strength was draining rapidly, but strangely, a faint, cool energy was flowing from deep within his eyes and spreading through his body.

Is it Cursed Energy? No, not quite. It was more like some form of life energy transformed by the Six Eyes, barely keeping his bodily functions from collapsing.

But it's not enough. If I just keep dodging, I won't last until dawn.

I have to fight back.

Moyu fixed his gaze on the Death Point at the Demon's neck. If I can attack there... but with what? He had no Nichirin Blade, no Wisteria Poison, not even a decent weapon.

Wait.

The Six Eyes granted him more than sight. Moyu could feel that his control over his body had reached an unprecedented level of precision. He could control how much each muscle contracted, sense the speed of his blood flow, and even faintly manipulate the weak energy inside him.

Breathing.

He suddenly remembered the key points of Water Breathing mentioned in the anime. Although he didn't know any specific forms, the basic principles of Breathing Styles were the same: using a special breathing rhythm to deliver as much oxygen to the blood as possible and enhance physical abilities.

He drew a deep breath.

Exhaled.

Drew another deep breath.

Something strange happened. In the Six Eyes' field of vision, the oxygen molecules he inhaled were efficiently separated and transported, and the efficiency of energy conversion in his blood soared. The cool energy flowing from his eyes began to resonate with the rhythm of his breathing.

"Playing tricks!" The Demon was evidently enraged. Its nails suddenly lengthened, turning into ten pitch-black blades. "Blood Demon Art: Shadow Claws!"

Black claw shadows swept toward him from every direction, cutting off all room to dodge.

Moyu's pupils shrank to pinpoints. Through the Six Eyes, those claw shadows were not solid, but concentrations of some kind of energy. They had "structures" and "nodes," especially the energy channel connecting them to the Demon's main body.

There!

Rather than retreat, he advanced.

Moyu charged into the densest cluster of claw shadows, twisting his body at incredible angles to dodge three deadly strikes. The fourth grazed his left shoulder, tearing away a piece of flesh, but he had already closed to within three paces of the Demon.

He pressed the fingers of his right hand together like a blade.

He compressed all his breathing energy, that cool energy, and his will to survive into his fingertips.

The Six Eyes locked precisely onto the Death Point, onto the most vulnerable "thread" in that knot of energy.

"Slash!"

There was no Nichirin Blade, no Breathing Style form. Only human fingers wrapped in a thin layer of energy, thrusting toward the Demon's neck.

The Demon laughed mockingly. How could human flesh possibly pierce a Demon's skin?

But it was wrong.

Moyu's fingertips didn't try to cut the skin. Like a needle, they pierced precisely into a "gap" in the Death Point's energy structure.

"Wh—?!"

The Demon's expression froze. It felt the blood of Lord Muzan inside its body fall into disorder for an instant. Though it lasted only a moment and caused negligible damage... how was this possible?!

"What did you do?!" The Demon flew into a rage and swiped a claw at Moyu's head.

Moyu wanted to dodge, but his body had reached its limit. The Six Eyes calculated the trajectory clearly—he couldn't avoid it.

Am I going to die?

No.

At that moment, some kind of "switch" deep within the Six Eyes was triggered.

Limitless—not the active techniques Blue or Red, but its most basic principle: manipulation at the atomic level, the "Infinity" that approached without ever touching.

The Demon's claw stopped an inch from Moyu's forehead.

It hadn't truly stopped; it was as if it had sunk into an invisible mire. Each millimeter it advanced required ten times, a hundred times the force. The space between claw and skin had been "stretched" infinitely.

"Th-this... what is this?!" Fear finally entered the Demon's voice.

Moyu was shocked by the phenomenon himself, but he didn't waste the precious opportunity. He pulled away, putting distance between them again.

A pale light appeared on the horizon.

"Damn it..." The Demon looked east, where a streak of gold was already seeping beneath the clouds. It glared fiercely at Moyu, that pair of azure eyes already etched deep into its memory. "Next time... next time I'll eat you for sure!"

The dark figure swept backward and vanished into the depths of the forest.

Moyu didn't give chase—he couldn't have even if he wanted to. Once he was sure the Demon had truly left, his legs gave out and he fell to his knees.

The Six Eyes automatically shut off the flood of information, retaining only a basic enhancement to his vision. Even so, a violent headache washed over him like a tide, as though someone were hammering his skull with a chisel.

[Ding. Demon detected to have fled. Newbie quest "First Survival" complete.]

[Quest rating: B (successfully survived, but failed to kill the target)]

[Reward: Coins × 200. Basic section of the exchange shop unlocked.]

[Hidden achievement unlocked: "Touching the extraordinary in a mortal body." Additional reward: Coins × 100.]

[Current status: critically injured (excessive blood loss, mental overload). Immediate treatment recommended.]

The system's notification made Moyu a little more lucid. Forcing himself to stay conscious, he called out in his mind, "System... are there... any treatment options...?"

[Available in the basic section: Medical Ninjutsu: Hemostasis Technique (50 Coins), Recovery Potion: small (100 Coins). Exchange?]

"Both... get them..."

[Exchange successful. Transmitting knowledge of the Hemostasis Technique... transmission complete. Recovery Potion stored in system space. It can be retrieved with a thought.]

A flood of knowledge about chakra control and stopping blood flow through acupoints poured into his mind. Gritting his teeth, Moyu followed the knowledge he had just acquired and guided the last bit of energy in his body—what he now knew might be a trace of "Cursed Energy" transformed by the Six Eyes—to the wounds on his chest.

The bleeding visibly slowed.

He then retrieved a vial of pale green potion from the system space, pulled out the stopper, and drank it in one gulp. A warm current spread from his stomach, and his strength slowly began to return. At least he wasn't going to die for the moment.

After all that, Moyu leaned against the tree trunk, gasping for breath.

He had survived.

Not only had he survived, he had gained the Six Eyes and activated the system.

His azure eyes shimmered faintly in the morning light. Moyu looked east, where the rising sun was slowly climbing, dyeing the clouds gold and red.

The world of Demon Slayer: Kimetsu no Yaiba...

Tanjiro, Nezuko, Mr. Giyu, Mr. Rengoku, Sister Shinobu Kocho, Kanao Tsuyuri...

Those people who had made him laugh and cry through a screen, whose stories had left him with lingering regrets, all existed in this world now.

"System," Moyu said softly, "what's the ultimate goal?"

[This system is intended to help the host alter the course of fate and make up for regrets. Main quests will be issued as the story progresses.]

Alter fate?

Moyu clenched his fist. The wounds on his chest still hurt, but a flame had kindled in his heart.

"Then I'll change it," he murmured, as though making a vow. "With these eyes, and every bit of power I can obtain."

Footsteps sounded through the mountain forest, steady and swift.

Moyu looked up warily, and the Six Eyes activated automatically. He saw a figure in a dark blue haori, with eyes like rippling water and a Nichirin Blade hanging at his waist.

Giyu Tomioka.

This future Water Hashira had evidently been drawn here by the sounds of fighting during the night. His gaze fell on Moyu, particularly his eyes, whose azure glow had not yet completely faded, and sharpened slightly.

"The scent of a Demon." Giyu's voice was calm. "Did you encounter one?"

Moyu nodded without saying much. He knew Giyu's personality, and he also knew what he should do now.

Giyu came closer and examined Moyu's wounds, then looked at the traces of battle around them—particularly the tree trunk torn apart by the Demon's claws, and the strange claw marks on the ground, their paths seemingly twisted by an invisible force.

"You drove the Demon away." It wasn't a question.

"I barely escaped with my life," Moyu answered truthfully.

Giyu was silent for a moment, then said, "Your eyes are unusual."

"...I was born with them."

It was an explanation Moyu had prepared long ago. There was no way to explain the Six Eyes, so he could only attribute them to an "extraordinary natural gift."

Giyu didn't press further. He simply said, "You need treatment. Come with me."

He turned and headed down the mountain at a measured pace, evidently taking Moyu's injuries into account.

Moyu struggled to his feet and followed. With every step, the wounds on his chest reminded him of this world's cruelty, but the warm flow of energy from the morning sun, conveyed by the Six Eyes, also told him—

A new journey had begun.

And on the system interface he couldn't see, a new notification was being generated:

[Key figure detected: Giyu Tomioka. Side quest triggered: obtain the Water Breathing inheritance. Reward: issued according to degree of completion.]

His azure eyes reflected the morning light, and the dark blue figure ahead of him.

Moyu took a deep breath and followed.