Isekai Adventure in the Dimensional Cube

Near the small town, in the forest of another deep mountain.

"Is this good enough?"

Reiger appeared here, holding a newly forged scabbard in his hand.

It was a scabbard just like Reiger's Sun Wheel Blade, entirely black with a layer of resin painted on its exterior.

This was the fruit of Reiger's nearly two-hour hustle through the mountain.

In order to create a scabbard that could contain the hermit's blade, Reiger had used magic to break down, extract, and smelt several kinds of resins. Ultimately, he refined a highly heat-resistant organic material and also managed to synthesize a high-density metal akin to tungsten. Combining the two, he finally crafted this scabbard.

"Clack..."

Reiger sheathed the hermit, which he had kept in his hand and which emanated heat incessantly, into the scabbard, eliciting a faint sound.

The length of the hermit's blade was just right; it was wholly enclosed by the scabbard, leaving only the hilt exposed.

"Very good."

Reiger's face bore a satisfied smile.

The feeling of personally crafting his own weaponry was indeed different from the initial sensation of simply receiving a weapon made for him by Chun.

"Now that the weapon issue is sorted, and the evolution of the breathing technique is completed exactly as initially planned, I guess I'm pretty much done with what I wanted to do in this world?"

If there was anything regrettable, it was that he hadn't been able to level up.

Before Dimensional Travel, Reiger planned to achieve great deeds in this world that would suffice for him to level up to Lv.6.

Unfortunately, this world didn't abound with monsters for him to conquer like Earth Mistake World did; not only were demons scarce here, but their strength was nothing to write home about.

In the eyes of the people of this world, the demons ranking high in their echelons were terrifying foes; but to Reiger, mere Lv.4 beings, he could have vanquished them with the flick of a wrist even before evolving his breathing technique, let alone now.

Even the legendary demon king and that upper echelon who surpassed all others by a tier, with power that was probably around Lv.5, could hardly be a match for Reiger, even though they were of the same level. Ordinary Lv.5s now, how could they possibly stand a chance against him?

Were he merely seeking a challenging opponent, that might be barely satisfactory, but what Reiger wanted was an enemy through which he could achieve great deeds.

What kind of enemy would enable one to achieve great deeds?

An enemy stronger than oneself!

Therefore, Reiger felt that he might not be able to achieve such greatness and reach Lv.6 in this world.

Consequently, the things Reiger wanted to do in this world were naturally drawing to a close.

His ability values had already reached their limits, and the potential and growth of his current level were thoroughly exhausted. Apart from leveling up, there was not much room for significant progression for Reiger now.

Under such circumstances, with nearly three months remaining before the conclusion of this Dimensional Travel, the only thing he might be left to do would be to while away the time.

"I could use the free time to practice swordsmanship, practice magic; perhaps that might allow 'Swordsman' and 'Magic' skills to advance by a stage or two."

"Also, I should be able to look forward to a confrontation with the demon king, right?"

"A demon king who has lived for a thousand years should be quite stronger than the upper echelons, and if the highest of those ranks might be Lv.5, then can I expect the demon king to be Lv.6?"

"But even if he is Lv.6, he probably won't be able to grant me any great deeds now, will he?"

"What should I do?"

As Reiger pondered lightly, he attached the sword to his waist and walked along the mountain path.

Until at a certain moment, Reiger suddenly stopped in his tracks.

He furrowed his brows and looked in a particular direction, then placed his hand on the hilt of his blade at his waist, ready to draw and strike.

"Please wait a moment."

Just before Reiger was about to draw his sword, a voice rang out.

"We mean no harm."

It was a very young-sounding female voice, yet it carried a mature, graceful, and charming cadence.

As the elegant female voice echoed, two people appeared without any prior indication in the direction Reiger was looking at.

They were a male and female duo.

The male was dressed very neatly, like a well-bred young man; his hair was also impeccably groomed, but his face looked rather fierce, giving the impression that he had a bad temper and was not to be trifled with.

The female was a beautiful lady with her black hair tied into a large, low bun. Her complexion was pale, yet her lips were rosy, and she wore a deep purple kimono decorated with light purple wave-like patterns and red flowers. A beige wide belt circled her waist, making her appear as if she too hailed from a wealthy family.

This male and female pair gave off the first impression of being siblings, with the sister standing in front, and the brother a step behind, clearly deferring to the former.

It was this sibling-like pair who had seemingly sprung from thin air and now stood before Reiger.

Looking at these two, Reiger's eyes moved imperceptibly.

He had already recognized their identities.

"Greeting Tsukiguni Yoriichi-sama."

The woman bowed deeply to Reiger.

"...I didn't expect to be detected before we showed ourselves."

The youth standing by his side, however, did not salute but instead revealed a displeased expression and muttered under his breath.

Reiger glanced at him and said indifferently, "Although the ability to obscure others' vision and create illusions is rare, it's a pity that in the 'world' I am currently seeing, it is useless."

"Tsk."

The youth clicked his tongue indiscreetly, his attitude quite disrespectful.

"Yushirou, show some manners."

The beautiful woman furrowed her pretty eyebrows and gently admonished the young man beside her.

"Yes, Miss Tamayo!"

The youth known as Yushirou immediately changed his rude demeanor to one of docility and obedience.

Reiger took his hand off the hilt of his sword, markedly interested in the two people before him.

Wrong, these two weren't human.

"Are you demons?"

Indeed, the man and woman before him were not human but demons.

The ability to block vision and create illusions was a demon's Blood Magic.

"I apologize for visiting you in such a manner."

The woman named Tamayo once again lowered her head to Reiger.

"Please forgive us, this is in the vicinity of Demon Slayer Corps Headquarters, and if we were to expose ourselves carelessly, it might lead to many unnecessary misunderstandings, so we had to come in this manner."

Her words were quite sincere, prompting an involuntary trust in her.

Of course, any other Ghost Hunter would never trust her regardless.

Demons are man-eating monsters, the very entities everyone in the Demon Slayer Corps loathes. Except for people like Tanjirou, who due to a special encounter and innate kindness, might feel trust because of the tone of the other party.

If Reiger weren't aware of the background of these two demons, he might feel the same way.

"So, demon miss, did you specifically come near the Demon Slayer Corps Headquarters in this manner just to see me?"

Reiger said so.

The moment the other party appeared, she called out the fake name Reiger used in this world, so obviously, she was here for him.

As for how she was able to find him and come to the Demon Slayer Corps Headquarters, Reiger wasn't surprised.

After all, he knew that despite being a demon, the woman before him who looked like a young lady from a wealthy family, was an ally who had connections with the Ubuyashiki family and stood in opposition to the Demon King.

She knew about his existence most likely because of that.

As Reiger pondered this, he heard Tamayo say,

"I did indeed come to see you, Tsukiguni Yoriichi." Tamayo looked at Reiger and said, "After hearing about your existence from Tanjirou, I was so restless that I finally resolved to meet you."

"From Tanjirou?" Reiger was surprised.

Not from Ubuyashiki?

"Yes." Tamayo nodded, explaining, "Tanjirou and I are old acquaintances, we have been in contact with each other. In his most recent letter, he mentioned you, saying that you are a powerful Swordsman who can easily slay Upper Moons, and he spoke highly of you."

"I see." Reiger acknowledged, then changed the topic, "But you didn't come out of curiosity about my ability to kill Upper Moons, did you?"

"...That's part of the reason too." Tamayo fell silent for a moment, then spoke softly, "I have been searching for someone capable of confronting the Demon King, so your strength is also one of the reasons that attracted me here."

Reiger calmly said, "But that's not the main reason, right?"

His gaze seemed to penetrate everything, allowing Tamayo to gauge the abilities of the legendary Swordsman for the first time.

Though it made Tamayo somewhat wary, she was more relieved.

To Tamayo, who stood against the Demon King, the more extraordinary Reiger was, the more reassured she felt.

Thus, Tamayo finally revealed the true purpose of her visit.

"After learning of your existence, I was indeed restless," Tamayo began. "To me, and to Kibutsuji Muzan, the name Tsukiguni Yoriichi carries such weight."

With these words, Reiger gave Tamayo a profound look.

"Have you met Tsukiguni Yoriichi?"

Though phrased as a question, Reiger's tone was filled with certainty.

"...Yes." Tamayo did not deny it, speaking slowly, "I have met Tsukiguni Yoriichi, that Swordsman strong as the Fire God. I also witnessed the scene where he almost killed Kibutsuji Muzan, a near-death encounter for Muzan."

That was indeed the case.

Tamayo, this female demon, could perhaps be older than any current Upper Moon in terms of years spent in this world.

In the Sengoku period, Tamayo was already a demon, and she had a time when she closely followed the Demon King.

Because of this, she was the only one who witnessed that scene.

She witnessed the encounter between Tsukiguni Yoriichi and Kibutsuji Muzan, and the memorable, fierce battle that ensued—the first and last of its kind in their lives.