The Journey Back and a Rise in Strength

The night gradually faded, and the horizon turned pale. Amid the faint smell of blood lingering over Mount Natagumo, the survivors set off on the road back to Demon Slayer Corps headquarters.

Giyu Tomioka walked silently at the front, his back straight as a pine as he led the group. Shinobu Kocho wore her trademark gentle smile, checking from time to time on Zenitsu Agatsuma, who was being carried on a stretcher by the Kakushi, and giving Tanjiro and Inosuke basic medicine for their wounds and sweets to restore their strength. Her movements were light and graceful, as if the fierce killing intent she had shown the night before had never existed. But Moyu could clearly sense that the occasional glances she cast at the wooden box on Tanjiro's back still held a trace of scrutiny and wariness that was hard to notice.

Tanjiro insisted on walking by himself. Though his steps were somewhat unsteady, his gaze remained firm. He carefully protected the wooden box on his back, in which Nezuko lay sleeping. Inosuke was much more irritable. His injured ribs made it difficult for him to move, and what infuriated him even more was that both his swords had broken in the fight with Spider Father. Now he could only go empty-handed, occasionally making a few slashing motions at the air and muttering things like "Damn it," "My swords," and "If only my swords hadn't broken."

Moyu walked near the back of the group. He appeared to be traveling quietly, but his mind had long since sunk into the system interface in his head.

[Current Coins: 65,800]

Killing Lower Rank Five Rui and the members of his "family," together with what he had accumulated from previous missions, had brought him considerable wealth. Now, he urgently needed to turn that wealth into tangible strength.

Although Moyu had ultimately won his fight with Rui, it had exposed his current weakness—his ability to sustain a high-intensity battle. Using Blue at full power consumed a terrifying amount of mental strength and energy, and since the battle ended, he had recovered only around thirty percent of his stamina and energy. Such a recovery rate would be a fatal weakness in a more intense, prolonged fight.

I have to deal with my recovery and energy reserves first, Moyu thought. The system's exchange list scrolled rapidly through his mind, displaying a dazzling array of abilities, bloodlines, and skills from countless worlds.

His gaze finally settled on one option:

[Sage Body Constitution (Beginner)]: A constitution unique to the Senju and Uzumaki clans, originating from the world of "Naruto." Greatly increases vitality, energy reserves, and physical recovery speed. Exchange price: 45,000 Coins.

Effects: Increases total energy by 100%, natural energy recovery speed by 200%, and stamina recovery speed by 150%. Significantly accelerates wound healing and increases resistance to negative effects such as poison and genjutsu.

Note: This is a beginner-level adapted version, designed to avoid a severe conflict with the rules of the current world. Deeper potential can gradually be unlocked as the host grows or through subsequent exchanges.

This is the one! Moyu made his choice without hesitation. The Sage Body's all-around improvements were precisely the foundation he needed most. Powerful recovery meant he could keep fighting longer, while larger energy reserves would allow him to use Blue more frequently and with greater power.

[Exchange confirmed: Sage Body Constitution (Beginner). 45,000 Coins consumed. Fusion beginning...]

A warm current instantly swept through his body, as if every cell had been infused with boundless vitality. His stamina, which had been recovering slowly, rapidly filled up like water rushing through an opened floodgate, while his depleted Breathing Cursed Energy regenerated at an astonishing rate. The soreness in his muscles and his mental fatigue quickly dissipated, as though brushed away by a spring breeze. The transformative sensation made Moyu let out a soft breath, and a faint, almost imperceptible luster flashed in his azure eyes.

After a while, the Sage Body Constitution finally fused with him successfully. Throughout the process, Moyu's stamina and energy had continued to recover at an accelerating rate.

[Fusion successful! Current status: Stamina 90%, energy 91%.]

Just by walking, he had already come close to a full recovery! That alone showed how powerful the Sage Body was.

He still had 20,800 Coins left and could continue increasing his strength, but what would be the most worthwhile exchange? Moyu continued browsing. He suddenly thought of Inosuke's broken swords and the tougher demons he might face in the future, such as Upper Rank Three Akaza, whose physical toughness was monstrous. This was indeed a problem—the penetrating power of his attacks and the durability of his weapon were also crucial.

Nichirin Blades were excellent weapons for killing demons, but they still risked breaking against extreme defenses or special Blood Demon Arts. Was there an ability that could strengthen his attacks while protecting his weapon?

His gaze fell on another option:

[Armament Haki (Intermediate)]: A power latent within the human body, originating from the world of "One Piece." It can increase a person's defense and attack power, acting like invisible armor. It can also be developed into an offensive force, allowing its user to contend with Devil Fruit ability users. Exchange price: 18,000 Coins.

Effects: Grants mastery of Armament Haki hardening and coating techniques. It can be applied to the body or a weapon, greatly increasing offensive and defensive strength. Provides some defense against energy attacks and special abilities.

Note: Intermediate mastery, including training in basic application techniques and directions for further training.

Armament Haki... Moyu's interest stirred. This ability could not only directly strengthen his body and weapon, but if the time was right, teaching the Demon Slayer Corps how to cultivate it would undoubtedly improve the members' overall chances of survival and combat strength. That would also be highly beneficial for future battles, building his reputation, and gaining a greater say. Earlier, even staking his life as a guarantee had not shaken Shinobu Kocho's resolve to eliminate Nezuko, largely because he was still just a Demon Slayer Corps member who had joined only recently.

Exchange!

[Exchange confirmed: Armament Haki (Intermediate). 18,000 Coins consumed. Beginning knowledge transfer and physical adaptation...]

Techniques for flowing, gathering, and hardening Haki poured into his mind like a sudden revelation. At the same time, his body seemed to undergo a subtle change, as if it had gained a kind of "fluid" energy he could command at will. Moyu quietly clenched his fist. With a slight shift of his thoughts, an extremely faint black sheen, almost impossible to discern with the naked eye, instantly covered his hand, giving his skin a metallic texture before quietly fading away.

It really is amazing... Feeling that power, he knew what he could do with it.

"Moyu, your complexion looks much better!" Tanjiro noticed the change in Moyu's aura and spoke with concern.

"Yeah, I rested a bit and recovered well." Moyu nodded and looked at Tanjiro and Inosuke, who was grimacing beside him. "How are your injuries?"

"I'm fine! They're just scratches!" Tanjiro said optimistically. Then his eyes dimmed a little. "It's just Zenitsu... and Inosuke's swords..."

"Hmph! They're just little scratches! Once I get new swords, I'm gonna find that big guy and fight him again!" Inosuke shouted defiantly, then sucked in a breath as the movement aggravated his wounds.

Moyu shook his head helplessly. Even if you want to fight him, you won't get the chance. That demon's ashes have already been scattered by now. He asked, "Tanjiro, what exactly happened with that big guy you ran into earlier?" The story had changed quite a bit because of his involvement, so he wanted to learn about Spider Father and see how much his strength had changed, giving him some idea of what to expect later.

Tanjiro immediately began recounting everything in earnest: how they had been separated, how they had encountered Spider Father, how Inosuke's swords had broken and he himself had become trapped in a desperate battle, and how Nezuko had awakened at a critical moment and helped them with her Blood Demon Art, Exploding Blood. Finally, he described how he had combined Water Breathing and Hinokami Kagura and joined forces with his sister to slay their formidable enemy.

"Nezuko... she really tried hard, and she was so brave." Tanjiro's voice was full of pride and tenderness.

Moyu listened quietly and formed a new assessment of Tanjiro and Nezuko's strength. Spider Father, meanwhile, had been considerably stronger than in the original story. Moyu had thought the current Tanjiro and Inosuke would have no trouble taking him down together, but he hadn't expected the fight to be so difficult.

"It's normal for swords to break," Moyu said, looking at Inosuke. "The Demon Slayer Corps' Nichirin Blades are sharp, but in some extreme situations, they still need to be reinforced with the user's own strength. I recently gained some insight and thought of a technique that might strengthen weapons and one's own defense. Once we reach headquarters, finish our business, and settle in, we can look into it together."

"Oh?" Although Inosuke remained defiant, he had seen Moyu's strength and was still a little curious about his "technique."

Tanjiro's eyes lit up. "Really? You're amazing, Moyu! You're always coming up with something new!"

Shinobu Kocho listened to their conversation from the side, her smile unchanged, though thoughts moved through her mind. This Moyu... not only has his strength grown amazingly fast, but he also seems to know some secret techniques. Mr. Urokodaki really did bring back an extraordinary child this time. And young Kamado and his sister... things are getting more and more interesting.

Giyu Tomioka remained silent, but a trace of almost imperceptible emotion flickered deep in his rippling eyes.

Over the next few days of travel, Moyu familiarized himself with his newly acquired Sage Body and Armament Haki while quietly using Haki to nurture his Nichirin Blade, Azure Star, making the blade look more subdued, its sharpness concealed. Not only had he fully recovered, but his overall strength had also undergone a qualitative leap.

With medicine and his own tenacious will, Tanjiro had recovered from most of his injuries as well. Inosuke still had difficulty moving, but he was energetic enough to give people a headache.

Several days later, a vast estate hidden deep in the mountains and protected by layer upon layer of barriers appeared before them. They had reached Demon Slayer Corps headquarters.

Guided by the Kakushi, the group passed through one gate after another and arrived before a spacious courtyard. They could vaguely make out several figures already gathered inside. Their auras varied in strength, but every one of them radiated a powerful pressure.

"Please wait here. The Master will arrive later," a Kakushi member said quietly.

Tanjiro clenched his fists somewhat nervously, while Inosuke looked around with curiosity. Moyu stood calmly to one side, his Azure Eyes sweeping over the indistinct figures in the courtyard. He understood.

The current Hashira had all gathered.