Zenitsu Agatsuma

After resting for two days at Tamayo's secluded residence, which was filled with the fragrance of medicinal herbs, the two decided to return to Mount Sagiri.

Before they left, Tamayo solemnly entrusted Moyu and Tanjiro with several specially made vacuum crystal test tubes. Fine runes were etched into their inner walls to keep blood samples viable. "Please be careful. None of the Twelve Kizuki should be taken lightly, especially the Upper Ranks... Your lives come first." Her warning was full of genuine concern. Though Yushiro still regarded Moyu with an apprehension he could hardly put into words, he silently prepared some highly effective wound medicine and antidotes and pressed them into Tanjiro's hands.

The journey back was less urgent than the one there. Tanjiro carried the wooden box on his back, and Nezuko, apparently more peaceful now that she was away from Tokyo's mingled scents, occasionally poked her head through a gap to gaze curiously at the scenery. As Moyu traveled, he repeatedly replayed his battles with the Hand Demon and Arrow Demon in his mind and, more importantly, considered how to further merge Limitless with Azure Flow Breathing.

The effects of "Energy Manipulation Mastery (Advanced)" continued to show. Moyu could feel his microscopic control over his breathing and Cursed Energy growing ever more refined. Like a master craftsman wielding a carving knife, he applied every bit of power exactly where it was needed, with minimal waste. As he traveled, he tried to incorporate the principles of Limitless more precisely into his movement. Rather than simply projecting a force field, he created tiny, directional fields of repulsion beneath his feet only at the instant they touched the ground. As if gliding over ice, he moved much faster, his movements became graceful and silent, and his stamina consumption fell further. He privately named this application "Azure Flow Breathing: Footwork: Flowing Cloud Step."

At the same time, he began devising a defensive sword technique with broader applications. Relying entirely on Inviolability still consumed an enormous amount of energy. If he could use sword techniques to guide it and form a sustained defensive barrier like Water Breathing's Seventh Form, then combine it with Limitless's Infinity property, he might be able to create a move that united offense and defense while consuming a more reasonable amount of energy. He tentatively named it "Azure Flow Breathing: Zero Form: Fourth Style: Circular Mirror." It was still at the theoretical stage and would need a great deal of practice to perfect.

After several peaceful days on the road, the familiar outline of Mount Sagiri came into view in the distance. But on the evening before they were to enter the mountains, a Kasugai Crow fluttered down onto Moyu's shoulder with a rolled-up letter in its beak.

"Caw! Urgent mission! Caw!" the Kasugai Crow cried shrilly. "Eighty li northwest, Kinutatsuki Town! For several days in a row, residents have mysteriously fallen asleep at midnight and woken listless and severely depleted! Demonic activity suspected! Mizunoto-ranked members Moyu and Tanjiro Kamado are ordered to investigate at once! Caw!"

Another mission? Moyu and Tanjiro exchanged a glance. The Demon Slayer Corps really did seem to be short-handed. New recruits like them needed to grow stronger quickly.

"Kinutatsuki Town..." Tanjiro sniffed the air. "It's not far. Moyu, should we go straight there?"

"Yeah." Moyu unfolded the map to check the direction. "The description sounds like a demon that specializes in mental attacks or draining vital essence. Demons like that usually aren't strong themselves, but their methods are strange, so we need to be extra careful. Let's get there and back quickly, before more people become victims."

The two changed direction and hurried toward Kinutatsuki Town. By the time they reached its outskirts, it was deep into the night. The town was utterly silent, without even a dog barking. A faint, cloyingly sweet smell tinged with decay hung in the air, making their heads feel slightly heavy.

"This smell... it's unpleasant." Tanjiro's brow furrowed, and Nezuko let out a soft, uneasy hum inside the wooden box.

Moyu activated his Six Eyes and swept his gaze over the town. Its energy field was strange, as though it were shrouded in a thin, sleep-inducing gray mist. Inside many of the homes, the residents' life forces were faint and flickering, like candle flames in the wind. At the center of town, a cold demonic aura carrying hypnotic fluctuations was faintly discernible.

"Over there." Moyu pointed toward an abandoned shrine in the middle of town.

The two slipped quietly into town and approached the shrine. The closer they came to the center, the stronger the drowsiness-inducing aura grew. Even Tanjiro had to concentrate harder to resist the urge to sleep, while Nezuko curled up in her box, seemingly disliking the environment intensely.

Just as they approached the shrine's torii gate, a subdued, tearful muttering suddenly came from the roof of a nearby house:

"Ugh... I'm done for, I'm done for... I'm really going to die this time... Why am I so unlucky? Why did I have to run into something this scary again...? Grandpa, save me... I want to go home and farm..."

Moyu and Tanjiro looked up at the same time. A boy in a yellow haori, with medium-short golden hair, was curled up in the shadows on the roof, clutching his Nichirin Blade. He was shaking like a leaf, his face covered in tears and snot. It was Zenitsu Agatsuma.

Tanjiro froze for a moment. He remembered the boy, who had been unusually... well... distinctive during the Final Selection. He was about to call out a greeting when Zenitsu jerked his head up like a startled rabbit. On seeing Tanjiro and Moyu, and especially after sensing that they belonged to the Demon Slayer Corps, he grew more terrified rather than relaxing:

"Aah! Two, two more of them! Are you demons? No... are, are you teammates? Ugh... but you're still scary! Don't come any closer! I, I can't do anything! I'll just hold you back!"

Seeing Zenitsu like this, Moyu understood. This was the genius who was normally timid as a mouse, but who could unleash the ultimate speed of Thunder Breathing once he fell asleep—or rather, lost consciousness. He spoke calmly, his voice quiet but carrying a strangely soothing power that pierced through Zenitsu's panic. "Zenitsu Agatsuma, calm down. We're Demon Slayer Corps members sent to investigate: Moyu and Tanjiro Kamado. The demonic aura here is unusual. Do you know anything?"

Under the gaze of Moyu's calm azure-blue eyes, Zenitsu felt a trace of composure return for no apparent reason. Though his body was still shaking, he became a little less incoherent. "I, I don't know either... I just got here... and, and I felt really sleepy. Then I heard a strange sound coming from the shrine... It sounded, sounded like someone was singing... So I hid here... Ugh... it's too scary..."

Singing? Moyu's Six Eyes immediately focused on the shrine. Sure enough, mixed into that cold demonic aura were extremely faint mental fluctuations, like a lullaby. Those fluctuations were spreading continuously, affecting the entire town.

"It's a sound-based Blood Demon Art," Moyu concluded. "It hypnotizes the townspeople with song and drains their vital essence. Zenitsu, can you tell exactly where the sound is coming from and what it's like?" He knew Zenitsu possessed extraordinary hearing.

At the mention of listening, Zenitsu seemed to regain a little focus. He cocked his head, and his face grew even paler. "It's... it's beneath the shrine's main hall... There's a cellar... The sound is coming from there... It's a woman's voice... very soft, but... but there's something about it that draws your soul away... Ugh... if you listen too long, it feels like your soul's going to be sucked out..." He clapped his hands over his ears, not daring to listen any longer.

"The cellar..." Moyu nodded. "Tanjiro, protect Zenitsu and Nezuko, and make sure you block out the effects of the song. I'll go in and deal with it."

"Wait! Moyu, I'm coming with you!" Tanjiro said at once. Though he felt a little dizzy himself, his resolve was firm.

"No. This demon's ability is suited to fighting groups and launching sneak attacks. The cellar is cramped, so more people would only get in each other's way. The demon itself shouldn't be strong. I can handle it." Moyu's tone left no room for argument. "Your job is to keep the townspeople and Zenitsu safe, in case it makes a desperate move."

Tanjiro met Moyu's calm gaze and nodded. "I understand! Be careful!"

Zenitsu looked as though he'd been saved, but immediately grew worried again. "Can, can you really do it alone? It sounds dangerous! Why don't we just run away...?"

Moyu didn't answer. His figure blurred, and he passed silently through the torii gate like a wisp of pale blue smoke, gliding toward the shrine's main hall. His Flowing Cloud Step showed astonishing results at that moment, causing almost no fluctuation in energy or sound.

Inside the shrine grounds, the hypnotic song grew clearer, winding toward Moyu's consciousness like invisible threads. But before the absolute perception of the Six Eyes and his strengthened mental power, a mental assault of this level was like a breeze brushing a mountainside, unable to shake him in the slightest. He pinpointed the hidden cellar entrance in the main hall, from which an even denser demonic aura seeped.

Without hesitation, Moyu leaped straight into the cellar.

The cellar was dim and damp. A female demon with a twisted face, dressed in a songstress's tattered clothes, sat in the center, her mouth open as she sang the eerie song. When she saw Moyu burst in, the song stopped abruptly, and astonishment and malice appeared on her face. "Another one who's awake? Your mind must be very resilient... Perfect. Draining your vital essence will surely be a great boost!"

She waved both hands, and the sound waves echoing through the cellar suddenly became sharp and piercing, stabbing at Moyu's mind like countless needles. It was an even stronger mental attack!

In the vision of Moyu's Six Eyes, however, the paths, frequencies, and weaknesses of those sound waves were perfectly clear. He didn't even use Inviolability. He simply concentrated his breathing and Cursed Energy around his ears, forming a tiny buffer barrier that easily neutralized the attack.

"A boring trick," Moyu said coolly, and his figure vanished in an instant.

All the female demon saw was a flash of azure starlight growing larger before her eyes. The next moment, a cold blade swept across her neck. She hadn't even had time to put up any meaningful resistance.

"Uh... how... is this possible...?" The female demon's head rolled to the ground, her face full of disbelief. The Blood Demon Art she relied on most had been reduced to child's play before this blue-eyed boy.

[Killed "Lullaby Demon," a demon skilled in mental attacks. Gold coins +3,800.]

The system notification sounded.

Moyu sheathed his blade and made a quick search of the cellar. After confirming there were no other demons or traps, he turned and left. The entire fight had been brief, efficient, and almost silent.

When he reappeared outside the shrine, Tanjiro and Zenitsu hurried over to meet him. The drowsiness-inducing aura over the town was rapidly dissipating.

"I-is it over?" Zenitsu stared wide-eyed at Moyu, whose clothes weren't even rumpled.

"Yeah. Just a minor demon that hypnotized people with its singing." Moyu nodded.

Tanjiro breathed a sigh of relief and smiled. "That's great! You really are amazing, Moyu!"

Zenitsu looked at Moyu, then at Tanjiro, and suddenly burst into tears. This time, though, he was relieved to have survived. "Thank goodness... We're really saved... Thank you both! Boo-hoo... I thought I was going to die..."

Seeing Zenitsu weep so hard, Tanjiro tried to comfort him, looking a little at a loss. Moyu's lips curved into a barely perceptible smile. Though their personalities were vastly different, this future companion seemed not to be quite as... useless as he appeared. At the very least, his extraordinary hearing might prove unexpectedly useful under certain circumstances.

The mission was complete, and the town's crisis was over. As the sky grew light, a new day began. Moyu, Tanjiro, and the newly joined Zenitsu Agatsuma, still somewhat shaken but no longer quite so panicked, set out together on the final stretch of the journey back to Mount Sagiri.

Sunlight dispersed the gloom of the night and shone on the three young swordsmen. Their road had only just begun, and the challenges ahead would surely grow more severe. But for now, another voice had joined the group, and though noisy, it added a different touch of color to their thorn-filled journey.