In the bottomless, spiraling passageway...
Footsteps echoed against the stone walls, making the space feel even more vast and silent.
Sōjun Minamoto had returned once again to the Tombs of the Star. He had temporarily set aside his thoughts on Tengen's evolution, turning instead to analyzing his soul.
The two were working in tandem.
Tengen was busy setting up a Barrier to delay his evolution for as long as possible—time was running out.
Sōjun stood nearby.
In his mindscape, Tengen's soul lay beneath a towering tree, on a flat expanse of grass. It gazed up at a sky full of stars. The stars shimmered, as if gazing back at him.
"Ever heard of a 'memory USB'?" Sōjun snapped back to reality, visibly excited. "It's like copying a person's memories and consciousness into a USB drive. When needed, you plug it into the brain and read it—restore your sense of self."
"??"
Tengen stared at him, confused.
Sōjun suddenly felt like he was trying to teach a village elder how to use a smartphone.
He tried another approach. "The soul and body are deeply intertwined. Both are essential to life. The challenge we're facing is how to bypass the Immortality Technique and separate the soul from the body."
He continued, "The word 'soul' is too broad—it includes spirit, will, memory, thought... What we can do is extract only the most vital part, let the rest evolve with the body, and then reinsert the core later to reclaim your sense of self."
He circled around Tengen.
"The next challenge is reintegrating that extracted part into the evolved version. The method matters. So does the timing. That part's up to you."
"...That's hard. Even I can't predict the direction of my evolution. I don't know what my body or soul will become. I'm not confident I could find myself again in the unknown," Tengen said after a moment of thought. His hesitation only deepened his resolve.
As expected, Sōjun found this troublesome. The biggest obstacle was still Tengen's personality.
"If worst comes to worst—discard the flesh, and ascend through the Barrier?" he offered as a last resort.
"You mean treat the Barrier as the body?"
"Exactly. If everything else fails, abandon everything else and store your consciousness in a Barrier. Don't you Buddhists emphasize spiritual cultivation? The body is just a raft for crossing the world. Once you've reached the shore, the raft's no longer needed."
Tengen looked speechless at the philosophical babble—but he still saw the logic in it.
"If it's already out of control, then we might as well separate the soul ahead of time... No, just the consciousness. Targeting only the consciousness would be much simpler..." Tengen muttered to himself.
"As long as we find a suitable vessel for the consciousness, we might even break free from the technique entirely—and achieve immortality," Sōjun pressed on while the iron was hot.
"Leave the rampaging body and incomplete soul to me... A problem that's plagued the jujutsu world for a thousand years gets solved, and the balance remains intact. What a cause for celebration!"
It was like that old riddle: "How do you fit an elephant into a refrigerator?"
Most people's first thought is that an elephant's too big and a fridge too small—not even minced meat would fit. Then they get stuck in that mindset.
In reality, it's just three steps: open the fridge, put in the elephant, close the fridge.
People's thinking always gets boxed in by assumptions. A typical household fridge holds about 100 liters, and people fixate on that number. But the question never said how big the elephant is—or how small the fridge.
Back to the real issue—it's simply a matter of how to move the elephant... or rather, how to extract the consciousness, store it externally, and find the right moment to reintegrate it into the soul. Even if fusion fails, the only concern is how to keep it functioning outside the body.
Sōjun's thinking was always unrestrained. If one method didn't work, there were always others.
For instance, he could use his own technique to fully assimilate Tengen—without erasing his consciousness. That would resolve the evolution problem completely. Of course, Tengen would never accept that. No one would hand over control of their life and death unless they had no choice.
There was also the possibility of partial assimilation—interfering with Tengen's evolution by having their techniques collide. That, combined with Tengen's own willpower, might even allow them to steer the direction of evolution.
Plenty of options. It all depended on what Tengen chose.
But no matter the method, developing something concrete and reliable would inevitably require experimentation on Tengen himself.
Sōjun didn't push. He gave Tengen space to think.
...
After a few days, Tengen finally made his decision.
Even at this critical juncture, he'd still dragged it out for several precious days. Sōjun Minamoto couldn't help but feel he was being far too indecisive.
His final decision—was to create a memory USB.
Sōjun Minamoto finally got his way, dissecting and researching him thoroughly.
A soul and body that had lasted a thousand years could certainly take a beating. But after repeated experiments, even Tengen had reached his limit.
"Why don't you go learn the Reverse Cursed Technique?"
It's all output and no recovery—even the toughest body can't keep up forever.
...
Sōjun Minamoto stepped out of the Tombs of the Star.
Cursed Energy in the Jujutsu World is negative energy. It typically functions through the combination of negative with negative—adding two negatives together.
This negative energy leans toward offense, but it's not suited for healing.
However, when you multiply negative Cursed Energy with negative Cursed Energy, the result becomes positive Cursed Energy.
That's the Reverse Cursed Technique.
This positive energy allows for physical healing, but it demands incredibly refined Cursed Energy manipulation.
Very few jujutsu sorcerers can pull it off. Even Satoru Gojo has only half-mastered it—he can heal himself but not others.
Sōjun Minamoto's skill in manipulating Cursed Energy was unquestionable, and he had already grasped the concept of "negative times negative equals positive."
What really stumped him was the very idea of "positive."
After all, the labels "positive" and "negative" are human constructs. Cursed Energy itself has no such inherent nature.
He could perform addition. He could perform multiplication.
But what was the meaning behind the "1" in (-1) × (-1) = 1?
It was precisely because he understood Cursed Energy too well that this narrow concept eluded him.
Time to find Gojo... or Shoko Ieiri.
If he could just see it once, he could slot it into a formula and fully grasp the Reverse Cursed Technique.
...
When Sōjun Minamoto found Shoko Ieiri, the three-person team was in class.
Masamichi Yaga was standing at the podium, lecturing. The trio below... well, aside from Suguru Geto, they were doing their own thing.
Sōjun Minamoto glanced up at the sky, pressed his face to the window, and mouthed:
"Be a teacher with dignity—Sensei, don't go over time."
Masamichi Yaga paused, refusing to look at the face in the window. After a moment, a vein throbbed on his forehead. He slammed the lectern. "Class dismissed!"
Running overtime had become such a habit that missing a day left him feeling hollow. Right now, Masamichi Yaga felt completely off. He walked out of the classroom and approached Sōjun Minamoto...
Sōjun Minamoto stepped around him and walked straight into the classroom.
"??"
...
He approached Shoko Ieiri, dragged a chair over, and sat across from her. Resting his right elbow on the desk, he asked, "Shoko, how do you use the Reverse Cursed Technique?"
"I know!" Before Shoko could answer, Satoru Gojo had already shoved his way in, repeatedly nudging him and trying to get his attention.
Sōjun Minamoto ignored him.
"Is this about Tengen-sama?" Suguru Geto walked over as well.
In his memory, Sōjun Minamoto could heal, though his methods weren't exactly gentle. Lately, he'd been wrapped up in Tengen-sama's evolution, and now he was suddenly asking about the Reverse Cursed Technique—it had to be related.
Sōjun Minamoto nodded. Not entirely, though.
He offered an explanation. "Tengen's soul can't withstand repeated experiments, and there's no time to wait for him to recover…"
"Wait, the Reverse Cursed Technique can heal souls?" the man in sunglasses interrupted again.
"Some people can use it that way," Shoko Ieiri finally got a word in. She looked at Sōjun Minamoto, envious of the kind of talent some people were born with.
Satoru Gojo crossed his arms when Sōjun Minamoto once again ignored him. "Shoko's explanations make zero sense."
He raised his fingers, mimicking her: "Stuff like 'First, you [startle] it, then go [whoosh] like this, and then [swish swish swish]...' Who the hell could understand that?"
"That's because you lack imagination," Shoko shot back.
"Who could possibly learn like that?!" Satoru Gojo cried out.
"I get it now," Sōjun Minamoto cut in, thinking for a moment and stopping their argument.
It was like how -1 always comes with a minus sign, but +1 often skips the plus. Positive Cursed Energy worked the same way.
Sōjun Minamoto fell into thought.
In a way, positive Cursed Energy should be the standard—it's more compatible with human sorcerers. So why is the Jujutsu world using the same negative Cursed Energy as Cursed Spirits?
...No, maybe Cursed Energy isn't inherently positive or negative. Maybe it's supposed to contain both at once?
A strand of blue Cursed Energy coiled around the tip of Sōjun Minamoto's right finger, glowing gently.
Did he really get it?
The three were stunned.
Then, a strand of black Cursed Energy began to wrap around the tip of his left finger.
The two fingers moved closer—black and blue slowly converging...
Ssshhh~~
It was as if they could hear the sound of water meeting fire.
The two Cursed Energies were canceling each other out.
Sōjun Minamoto frowned. Were they incompatible?
Or was he still doing something wrong?
As expected—it wasn't going to be that easy.