Rebirth From Ordinary Person To The Strongest

"A demon blade…?"

I asked, perplexed by what Renji-san had just said.

Renji-san kept his cheerful tone as he explained further.

"Yes, that's why you're here in Gifu, after all."

Though even he seemed unsure why Gifu specifically was the right place to craft a demon blade. What does Gifu have to do with it?

Apparently, I wasn't the only one confused. Aya, standing next to me, piped up. Stay tuned to M-V-L

"Dad, why Gifu if it's to make a demon blade?"

"Well, there's a place here that was famous for forging swords back in the day. It's known as one of the Five Great Sword-Making Regions. Gifu happens to be one of them."

"Really? But they never taught us that in school…"

"Well, nowadays only exorcists use swords, so I guess it's no longer common knowledge."

True, maybe it makes sense. Japanese swords are incredibly expensive, though—about as much as a car. As I considered this, I reset my thinking.

Actually, the real question was:

"Renji-san, what exactly is a demon blade?"

Renji-san smiled as if he'd been expecting the question.

"When exorcists refer to a 'demon blade,' it can mean two things. One is a sword with a dark history—a weapon involved in many deaths or that drives the wielder to kill. Those sorts."

"…Isn't that basically a monster?"

"In some cases, yes. It could be a possessing-type demon attached to an object rather than a person."

That… exists?

"But that's not what I'm talking about here. In this case, it's a sword forged by a skilled blacksmith, crafted from a relic."

"…Forged from a relic?"

I glanced down at the three relics hanging around my neck. These relics, left behind by Sixth Rank demons after their deaths, are almost indestructible—surviving even my spell "Oborozuki," which can swallow anything, magic or material alike.

But to process a relic…? Is that even possible?

"So, can relics actually be processed?" I asked.

"Apparently, yes. Blacksmiths are able to do it."

His answer was indirect, so I decided to change the question since it seemed unlikely he'd offer more details.

"What benefits are there to having a demon blade?"

"Oh, plenty. A demon blade can harness the magic of a Sixth Rank demon. You might have heard of a weapon called 'Chisui,' for instance?"

"Chisui…?" I thought, recalling the word vaguely. But it wasn't for "flood control," like I initially thought. Renji-san chuckled at my puzzled expression.

"It means 'Blood Drinker.' This sword is also a demon blade. When it cuts a demon, it absorbs that demon's magical energy."

"Absorbs it…?"

"Yes, literally. If you slay a First Rank demon with it, the sword stores that level of magical energy, which the wielder can then access. Think of it as an external magic tank."

"What?!"

Aya tugged on Renji-san's sleeve, her curiosity piqued.

"Dad, then can anyone use that sword to become a Seventh Rank like Itsuki?"

"In theory, yes, but in reality, it's not that simple."

Renji-san shook his head.

"Chisui has a condition: it only absorbs magic if you deliver the killing blow to the demon with it."

"Oh…"

Aya's voice trailed off in disappointment.

"Besides, 'Seventh Rank' is a level even the Kanzatsuki family can't fully measure. Sure, if you defeated dozens, maybe hundreds, of Sixth Rank demons, it might be possible to reach Seventh Rank. But no exorcist has done that—ever."

"Oh…"

Aya furrowed her brows.

"Also, Chisui only stores magic. Once used, the stored magic decreases. Do you understand what that means?"

"…You have to keep slaying demons to recharge the magic."

"Exactly."

Renji-san nodded deeply, his face reflecting an awareness of Chisui's limitations as if he'd had firsthand experience. Curious, I decided to ask.

"Renji-san, where is the Chisui sword now?"

"It's with my family."

"Huh?"

His casual answer left me momentarily taken aback.

"The Shimotsuki family has passed it down for generations. But since I often team up with Souichirou, I don't really need it."

"Oh, I see…"

When Renji-san and my dad work together, Renji-san typically acts as support. It made sense that he wouldn't need it.

Does this mean there's a demon blade in my family as well?

Now that I think about it, my dad does carry a sword when he goes on jobs. Could it be a demon blade?

I should ask him sometime.

Having gotten my answers, I turned to Ireina.

"So, is it true that I'm here to forge my own sword?"

"Yes, it's true," Ireina confirmed with a nod.

"I felt it would be a bit much to use everyone's time solely for Nina's recovery… So I thought, since we'd be here anyway, it would be worthwhile to craft a weapon for you, Itsuki. And of course, you may not know this, but there are only a few remaining master demon-smiths in the world, and one of them is here."

This was news to me.

"Are there really so few who can forge demon blades?"

"Yes. They're not quite as rare as Seventh Rank exorcists, but they're still exceptional."

Then, having a demon-smith in Japan isn't so strange…?

As I was coming to terms with this, Ireina continued.

"A demon-smith's workshop is typically located in places where earth energy flows strongly. So, I thought it would be beneficial for Nina to be in such an environment as well."

I took a moment to absorb her explanation, then nodded. Given the circumstances, it made sense.

We came to this hot spring to help Nina's mental recovery by exposing her to the life energy emanating from the earth's veins. And since demon-smiths work in areas with a high concentration of such energy, we could accomplish both goals at once.

But to process a relic…? I wonder what that entails.

For instance, if Chisui could theoretically serve as an external magic tank, what kind of powers could a blade forged from the Thunder Child's relic wield? Could it amplify my lightning magic beyond its usual limits? Or if it were crafted from Harunaga Adashino's insect relics, would it allow me to use some form of ancient spellcasting…?

Or what if it were made from the Puppet Marionette relic that caused such chaos in England…?

While I pondered these possibilities, my father entered the lobby. His mere presence caused a ripple of tension among the other guests; after all, a one-eyed man of his build was hard to overlook.

Renji-san turned to him as he approached us.

"Souichirou, you didn't tell Itsuki about the demon blade?"

"…Hmm? Did you already mention it?" my father asked.

Renji-san looked slightly abashed.

"Should I have kept it a secret?"

After a short pause, my father gave a small nod.

"No, don't worry about it. I… wanted it to be a surprise for Itsuki."