Waifu-fying Mirokuji Kirigiri and turning her into a Yoto-hime—a Demon Sword Princess. This was the exact thought that popped into Mahito's head the very first second he laid eyes on the blade. And as he successfully cultivated her into a true Tsukumogami, that desire had only grown uncontrollably more deranged.
But unfortunately, despite Mahito trying for a long time, there had been no progress. He had specifically consulted Kenjaku about it. Kenjaku hadn't shot the idea down immediately; he theorized that combining the Construction technique with Idle Transfiguration held far too many variables, meaning it wasn't strictly impossible.
But attempting something like this was completely unprecedented in the history of Jujutsu society. It was entirely uncharted territory. No Sorcerer had ever researched it.
At least the 'Half-Cursed Spirit' research had a theoretical foundation. Kenjaku had even attempted to cultivate them in the past. In other words, while Half-Cursed Spirits had never actually appeared in the original canon, their underlying theory was sound—they weren't just a baseless fantasy.
But waifu-fying a sword? There wasn't even a basic theory for it. Even with Kenjaku's vast expertise, he was stumped. So, he referred Mahito to someone else: the ancient sorcerer, Yorozu.
According to Kenjaku, during his thousand years of wandering, he had met the most brilliant Construction users of every era. Yet, even after a millennium of observing the very best, Yorozu remained leagues above the rest.
With Yorozu's help, combined with Mahito's millennium-unique Idle Transfiguration, anthromorphizing a Tsukumogami—something never achieved in Jujutsu history—might actually be possible.
Or so Kenjaku had claimed.
And now, Yorozu was standing right in front of Mahito. And her answer was—
"Impossible," Tsumiki asserted. "Give up, Mahito."
Because they weren't sure who had cast the barrier over Tsumiki, Mahito's group hadn't dared to linger at the hospital. Once they confirmed she was willing to follow Mahito temporarily, they headed straight back to their base.
And now, Tsumiki was standing in the room specifically dedicated to housing Kirigiri. She carefully inspected the Tsukumogami forged from a replica of the ancient blade, Futsu-no-Mitama. Taking Kirigiri off the sword stand, she gently drew the blade from its scabbard. The straight-edged greatsword, over two meters long, let out a crisp, airy metallic ring as it was drawn.
She stared at the ancient blade Tsukumogami, praising it. "Impeccably cultivated. Its spiritual essence is flawless. If you hadn't explicitly told me Mirokuji was cultivated for less than two months, I would have thought I was looking at a Tsukumogami over three hundred years old. She's a beautiful girl; I can feel her quiet elegance, like a white swan floating peacefully on the water."
"Just by looking at her, I know how much you love her." Tsumiki looked up at Mahito, furrowing her brow. "Repairing her is simple. Give me two days and it'll be done... But I don't understand why you want to turn her into a human. What's the point?"
Mahito thought about it very seriously. "Because it's cool."
Tsumiki's mouth twitched. "I hope you're joking."
"I'm not joking. I am incredibly serious." Mahito declared loudly. "Real men love sword girls!"
On the way over, Tsumiki had already learned that Ashiya Sadatsuna was here. Originally, she had planned to visit him first. A millennium ago, their relationship had been incredibly bizarre—through no fault of Ashiya's; Yorozu had caused all the drama herself. Now, Tsumiki naturally didn't want to deal with that awkward dynamic. She just wanted to have a normal conversation with an old friend.
In Tsumiki's eyes, Kenjaku barely counted as a friend. Compared to Kenjaku, she trusted Ashiya Sadatsuna far more.
But since Ashiya was currently busy teaching the five newly-born intelligent Cursed Spirits alongside Hanami and Dagon, he couldn't come over immediately. Kenjaku had gone to fetch them personally, leaving Mahito to bring Tsumiki here to examine Kirigiri first.
She assumed that repairing Kirigiri would be enough to repay Mahito's favor for awakening her, and she was supremely confident in doing so. She was acknowledged by the millennium-old Curse User Kenjaku as the strongest Construction user in a thousand years. Even if the ancient blade Tsukumogami had suffered structural devastation from taking a Black Flash head-on, fixing it would be child's play for her.
As she had said herself, two days would be more than enough.
The duel with Yuki Tsukumo was scheduled for the Kyoto Goodwill Event a week from now. During that timeframe, Satoru Gojo would be stuck at Tokyo Jujutsu High. Taking advantage of that window, Mahito could have a proper samurai duel with Yuki.
Time-wise, it was more than enough. Mahito had no complaints about that.
But if there was an even greater possibility, how could Mahito not chase after it? Yoto-hime was right in front of him!
Mahito couldn't hold back. He just couldn't!
In response, the strongest Construction user in a millennium spoke to him with heavy, patronizing patience:
"Mahito, a sword cannot turn into a human. Snap back to reality."
"Even you can't do it?"
"This isn't a matter of whether I *can* do it or not." Tsumiki spoke with the exact tone Miyu Edelfelt used to tell Illya *'humans cannot fly'*. "The structural disparity between a sword and a human is visibly astronomical without even needing to study it. A Construction user needs fundamental theories to construct even basic Cursed Tools.
"What you're asking for doesn't just lack theory—calling it a fantasy would be putting it nicely. It's pure delusion!"
"Can't you try really hard?" Mahito looked at her expectantly.
"Trying hard won't do a damn thing. Give it up," Tsumiki said deadpan.
Mahito was deeply disappointed.
Tsumiki sighed. "I can understand the attachment a swordsman has for his favorite blade. Swordmaster Ashiya used to hug the sword I gave him even when he bathed and slept. It wasn't until Lord Sukuna snapped it in half that his psychotic obsession slightly lessened.
"And I emphasize *slightly*. He still obsesses over that sword to this day.
"I'm guessing he still hasn't used another sword since, because he treated that blade as his life's ultimate pursuit. It was a bond deeper than romantic love.
"I suspect he still keeps the broken pieces. Lord Sukuna's cleaving technique is flawless, so the cross-section of the severed blade must be incredibly pristine. It would be very easy to maintain.
"If swords truly could turn into humans, I have no doubt he would become even more fanatical about it than I am about Lord Sukuna."
Mahito recalled Ashiya's reaction upon seeing Kirigiri a week ago, and completely agreed with Tsumiki's assessment. That old man Ashiya was exactly that kind of person!
"Kenjaku once said that if anyone in this world could anthropomorphize an ancient blade, it would be Miss Yorozu," Mahito said. "He spoke very highly of you. I've heard many stories about your feats from him. The most stunning one was your 'Insect Armor'. I figured that if it was you, you could pull this off. Placed in the modern era, your Insect Armor is basically the original Kamen Rider."
*If you could literally recreate Kamen Rider, then making a sword-girl should be possible too, right?* That was exactly what Mahito was banking on.
Tsumiki frowned. "Kamen Rider?"
"I remember your 'Insect Armor' mimics the exoskeleton of bugs. How is that not the original Kamen Rider?"
"My 'Insect Armor' isn't some fantasy ripped from a Tokusatsu show. It's a highly sophisticated scientific concept," Tsumiki corrected. "I used to be deeply frustrated by the Construction technique's overwhelming flaw: its pitifully inefficient Cursed Energy yield. Although the total Cursed Energy output rivaled any powerhouse of the Heian Era, the severe consumption rate crippled its effectiveness in head-on combat."
This was the bottleneck of all Construction users, a hurdle not even the strongest in a millennium could escape.
In the original canon, Maki's twin sister, Mai Zen'in, was also a Construction user. The matter generated by the Construction technique doesn't disappear after the technique ends, meaning the Cursed Energy consumption is agonizingly high, taking a massive toll on the user's body.
Mai Zen'in's absolute limit, before incurring severe physical backlash, was creating exactly one bullet a day. With that kind of drain, frontline combat was mathematically impossible.
"It was around then that I heard a rumor. They say a certain type of hawkmoth can fly across oceans, and hornets can fly over 25 miles a day. Not only that, but insects can lift objects hundreds of times their own body weight. Relative to their size, they exert an immeasurable amount of bite force, jumping power, and speed."
Tsumiki spoke with pride:
"Therefore, an insect's exoskeleton is the absolute pinnacle of the Construction technique. It draws out the technique's maximum output. By donning the 'Insect Armor', I can unleash strength, speed, and durability hundreds of times greater than a normal human, and gain the ability to fly.
"While it lacks the bizarre, esoteric effects of other Cursed Tools, its sheer raw output alone makes it unrivaled under the heavens."
Mahito's mouth twitched. "How is that *not* the original Kamen Rider?!"
The lore behind the original Kamen Rider was almost identical to this. Calling it an exact copy might be a stretch, but the overarching concepts matched perfectly. In the original canon, when Yorozu equipped her Insect Armor, she literally looked like a Kamen Rider.
"It's completely different," Tsumiki explained patiently. "My Insect Armor is constructed on the fly. In my era, I couldn't properly explain it. But in this modern age, where science and technology have far surpassed the past, I can explain it using modern terms:
"The reason insects can generate such immense output isn't just because of their physical structure. The most critical factor is their extremely light 'weight'. If you were to scale an insect up to the size of a human, they would absolutely be incapable of lifting hundreds of times their own weight. In fact, if they were truly that massive, they wouldn't even be able to take a single step.
"This is exactly why the Insect Armor generated by my Construction technique cannot be maintained indefinitely. The moment I don the armor, my Cursed Energy is actively warring against the physical laws of this world. I have to constantly bleed Cursed Energy just to keep the Insect Armor stable.
"That is why, even though matter created by Construction usually remains permanently, my Insect Armor is strictly a single-use construct."
"Was Kamen Rider like that?"
"I am still human. I am a human wearing Insect Armor.
"But the original Kamen Riders... their biological structures are no longer human."
Mahito frowned. "No exceptions?"
"Of course there are no exceptions!" Tsumiki stated firmly.
"But I did it."
"You did what?"
"I achieved exactly that—making a biological body that shouldn't exist permanently stable, and perfectly adapting it to my entire being." Mahito extended a hand, holding it right in front of Tsumiki's eyes, and smiled. "I created a physical vessel that perfectly aligns with me, a Cursed Spirit. And right now... I am standing right in front of you."
Tsumiki froze. "You aren't using an incarnated vessel?"
"I'm not." Mahito said meaningfully. "My body is exactly identical to my soul."
"That's impossible!" Tsumiki immediately grabbed Mahito's hand. Mahito could clearly feel her Cursed Energy invading his body, but he didn't resist, allowing the energy to spread through him.
This revelation seemed to severely agitate Tsumiki, completely wiping away the calm composure she had maintained until now. She closed her eyes, analyzing the state of Mahito's body, and spoke rapidly:
"From the moment a human is born, the synchronization rate between their soul and their body is innately 100%. This is an absolute law that Jujutsu society hasn't been able to crack since its inception.
"In the history of Jujutsu, 'Seance' techniques have existed. They allow a dead person to possess the living. The 'summoned' soul retains its memories and abilities, and even remembers how it died. It's been verified that it is indeed the genuine soul of the deceased.
"But if we've already breached the realm of Seances, why hasn't there ever been a true resurrection in Jujutsu history?"
"Because of the synchronization rate between body and soul!
"A 'summoned' soul can only exist because the technique's effect is acting as life support. And sustaining a technique constantly drains Cursed Energy. In other words, the moment the vessel's Cursed Energy runs dry, the 'summoned' soul will be dragged back into death, no matter how much it protests.
"But if you achieved 100% synchronization... doesn't that mean a 'summoned' soul could flawlessly co-opt everything from the vessel?
"If you truly can forge physical bodies that shouldn't exist, it means that as long as you find someone to cast a Seance technique alongside you, you could achieve a divine authority never before seen in the history of Jujutsu—"
"—True Resurrection."
This was something Mahito genuinely hadn't considered. It was exactly as Tsumiki described—if paired with a Seance Technique, could he truly perfectly resurrect a person? Mahito wasn't sure.
Perhaps, if the opportunity arose, he should test it out.
As expected of the strongest Construction user in a millennium. This was something even Kenjaku hadn't thought of, yet Tsumiki had instantly deduced the possibility through her sheer mastery and understanding of the Construction technique.
Tsumiki's voice had been incredibly rushed at the start, but the further she explained, the slower she spoke, until her voice entirely lost its usual imperious calm.
She opened her eyes, staring blankly at Mahito, and asked in utter disbelief, "How exactly did you do it?"
"Human Transmutation," Mahito blurted out instinctively.
Tsumiki snapped. At this exact moment, she finally unleashed the deranged, lunatic aura of the ancient sorcerer Yorozu. Just seconds ago, she had been calm and analytical, but now she began screaming like a schizophrenic.
She roared furiously: "Don't screw with me! Do you think I haven't read *Fullmetal Alchemist*?! Let me tell you right now, 'Equivalent Exchange' is absolute dogshit when applied to Jujutsu! Human Transmutation is the dogshit among dogshit! Even the transmutation circle formula Edward uses in the manga is scientifically incorrect!"
*Wait, it's incorrect?* Mahito actually didn't know that. He was a fake fan. He knew what Human Transmutation was, but he had never studied it closely.
*Hold on, why does Tsumiki know so much about Human Transmutation? She even knows Edward Elric's alchemical formula is wrong?! Could she be... a total weeb?*
Of course, there was absolutely no way Mahito was going to say that out loud.
"Kenjaku once said that the development of Cursed Techniques evolves alongside the development of human civilization," Mahito said slowly and methodically. "The way humanity perceives a concept determines the effect of the technique. The execution of all techniques relies on the caster's own cognitive understanding of the world.
"Miss Fushiguro, in the Heian Era, your Insect Armor was undoubtedly a world-shaking marvel. But what if we put it in today's context?"
"Even in the modern era, my Insect Armor remains the absolute pinnacle of Construction," Tsumiki said haughtily.
"And compared to modern ultimate weapons?" Mahito asked.
What was the modern ultimate weapon? Nuclear warheads.
Only a nuke deserved that title.
Tsumiki frowned. "I just told you, Construction is a technique with abysmally low Cursed Energy efficiency. I obviously know that constructing a nuke would be far more powerful than the Insect Armor, but no one can do it.
"Leaving aside how a single human brain is supposed to memorize blueprints that could fill a warehouse, even if you did memorize them, unless you had infinite Cursed Energy, you couldn't possibly construct it.
"The Insect Armor isn't just incredibly strong in frontline combat; it's also incredibly efficient. Otherwise, if there truly was a divine weapon a millennium ago, why wouldn't I just mass-produce a thousand 'Swords of Totsuka' and fight with those? Who would be my match then?"
"No, infinite Cursed Energy does exist," Mahito said.
"What?" Tsumiki was stunned.
Mahito smiled. "A third-year student at Tokyo Jujutsu High, Kinji Hakari. His Domain Expansion grants him literal, true infinite Cursed Energy. Because the overflowing Cursed Energy is so massive, it automatically triggers Reverse Cursed Technique, granting him genuine immortality.
"By the way, he works for me now. The reason I can confidently duel Yuki Tsukumo a week from now is precisely because he'll be holding Satoru Gojo back, leaving me with no rear-guard worries.
"When he gets back, I'll introduce you."
Tsumiki wore a look of utter disbelief. In the eyes of an ancient person, the concept of 'infinite Cursed Energy' was probably as absurd as a perpetual motion machine. She never could have imagined that true infinite Cursed Energy actually existed.
Mahito said slowly, "You find my ability to achieve Human Transmutation unfathomable, yet you fail to realize I feel the exact same way about your ability to create the Insect Armor.
"The first time I heard you could create Insect Armor, my immediate thought was, 'Isn't that just the original Kamen Rider?' After talking to you, I'm even more convinced—it *is* Kamen Rider.
"It's like the main character of a Tokusatsu show walking right into reality.
"No matter how much you deny it, no matter how 'mature' your theory is, if we look across a thousand years of history, no other Construction user has been able to replicate what you did. Why can't they do it?
"Because they also feel that your Insect Armor is un-Jujutsu, unscientific, and incomprehensible.
"So, what's the real difference here?"
Tsumiki looked thoughtful. She spoke slowly, "The comprehension of the technique... and the feeling."
Mahito nodded, smiling. "Kenjaku told me that you once said the most important aspect of the Construction technique is the 'feeling'. As long as the feeling is right, and you have a passable theory, you can construct matter that doesn't even exist in this world. I believe your 'Perfect Sphere' followed this exact principle?"
Tsumiki nodded. "Yes. The 'Perfect Sphere' is a theoretical existence. It exerts infinite pressure. Theoretically, nothing in the physical world can touch it. Paired with my Domain Expansion, unless the opponent has a way to neutralize it, no matter who they are, they will absolutely die."
Unfortunately, it was adapted to early by Sukuna and destroyed by Mahoraga.
Truth be told, Mahoraga was undeniably the most broken Shikigami in the entire Jujutsu universe. Hundreds of years ago, it mutually killed a Gojo clan head who wielded the exact same Six Eyes and Limitless combo as Satoru Gojo. Hundreds of years later, in the modern era, it was still able to adapt to the very fabric of space itself, allowing Sukuna to expand his technique and unleash the unprecedented 'World-Cutting Slash', killing Gojo in a single strike.
"My Human Transmutation is the exact same thing." Mahito smiled. "You think it's un-Jujutsu, unscientific, and incomprehensible simply because you haven't perceived it. Once you do, you'll change your tune easily enough."
Tsumiki fell silent.
After a long pause, she finally spoke hesitantly, "Are there any manga about swords turning into humans? I want to read them."
Mahito grinned. "Leave it to me!"
"Also," Tsumiki asked earnestly, "what season is Kamen Rider on now? I want to watch it. Oh, right, and I remember there was *Bio Booster Armor Guyver*... I vaguely recall there was some Zoalord who could simulate a black hole?"
Mahito went entirely numb. *Are you planning to undergo a hyper-evolution right now?!*