Akoto walked to the wreckage where his haori had been left intact by Tengen's residual barrier. He picked it up calmly and draped it over his shoulders, adjusting the fabric as if he were merely finishing another ordinary training session.
Even so, his fingers took half a second longer than usual to tie the sash.
He sighed.
"What a hassle… using the Four Fundamental Forces really is exhausting."
It was fatigue.
As he left the arena, his mind was already at work.
Akoto was not the type to celebrate victories; he analyzed flaws.
And despite the overwhelming victory, there were clear weaknesses that needed to be resolved.
Soul Manifestation had two distinct modes of operation: internal and external.
Internally, Akoto actively accessed direct control over the Four Fundamental Forces.
Gravity.
Electromagnetism.
The Strong Force.
The Weak Force.
And that was where the problems lay.
The first weakness—and the most concerning—was control.
Fundamental forces were not ordinary techniques.
They were not bursts of energy shaped by imagination or emotion.
They were the very pillars of reality.
Manipulating them required constant mental calculations: structural comprehension, fine adjustment of intensity, direction, range, and precision.
Distance, the amount of force applied, and stability depended entirely on Akoto's knowledge, skill, and mental endurance.
At present, his safe operational limit was roughly fifty meters.
Anything beyond that required exponentially greater effort.
Precision dropped drastically, and the risk of instability increased.
In long-range combat, that was an obvious vulnerability.
The Strong Force Sphere had been the perfect example.
Controlling the explosion's radius, limiting the emission of nuclear energy, containing the detonation's reach, and preventing the shockwave from surpassing the arena had required absurd concentration.
A single mistake would have vaporized far more than he intended—including allies.
He won.
But he had been at the very edge of control.
The second weakness was physical.
The human body, no matter how trained, was still a biological vessel.
When manipulating the fundamental forces, part of the energetic reaction inevitably reverberated back onto himself.
It was like standing at the epicenter of a cosmic phenomenon and pretending there was no impact.
Gravitational pressure compressing tissue.
Electromagnetic stress on the nervous system.
Nuclear tension vibrating at the microscopic level.
Thanks to the rigorous training under Tengen, his body had been strengthened far beyond normal standards.
That allowed him to manipulate at least two forces simultaneously without collapsing.
But that was still a limit.
Using three required extreme caution.
All four—like he had done today…
Resulted in the deep exhaustion he now felt in his bones.
Akoto closed his eyes for a moment as he walked.
He was fifteen years old.
Compared to the other heirs, he had less formal training time, less practical experience, and less technical refinement. Yet, thanks to his innate talent and the singular nature of his soul, he had reached the same level—and surpassed it.
But that wasn't enough.
If he declared himself the Strongest, he could not accept limitations that obvious.
Fifty meters needed to become five hundred.
Two simultaneous forces needed to become four without exhaustion.
Despite the clear weaknesses in internal usage, Akoto also possessed advantages that placed him on a completely different level from the other heirs.
The main one was structural.
His "spells" based on the Four Fundamental Forces were not, in fact, spells.
They did not use Cursed Energy as direct fuel. They did not depend on flow, formula, seals, or ritual construction. The manipulation of those forces was executed purely through the power of his soul interacting with the pillars of reality.
In practical terms, that meant his techniques could not be canceled.
Not by the Angel's techniques. Not by energy suppression. Not by any interruption mechanism that existed in that era.
The reason was simple: there was no Cursed Energy to disperse.
Only the Soul Manifestation consumed CE to remain active as an innate technique. But his main arsenal—Gravity, Electromagnetism, the Strong Force, and the Weak Force—was triggered by a deeper mechanism, one that preceded cursed energy itself.
It was the soul imposing laws.
To cancel that would require directly interfering with the essence of Akoto's soul—something that, as far as he knew, no one was capable of doing.
That was his first great advantage.
The second lay in the external use of Soul Manifestation.
If the internal use granted him control over the foundations of the universe, the external use transformed his very existence into a physical phenomenon.
When activated outwardly, his soul released an immaterial compound he called Spiritual Pressure.
It was not energy in the conventional sense.
Not a visible aura.
It was pressure.
The physical force generated by the presence of an absurdly dense soul being released into the material world.
This Spiritual Pressure distorted the environment. The air grew heavy. The ground trembled faintly. Living beings struggled to breathe—not from lack of oxygen, but from existential compression.
More importantly, it allowed Akoto to sense other souls.
Not as energy signatures.
But as real masses occupying space.
He could locate them, measure their density, evaluate their stability, and even press directly against the structure of another person's soul. If he increased the intensity, he could crush it. And because body and soul were intertwined, spiritual destruction would inevitably drag the physical body down with it.
At first, he used this Spiritual Pressure in a simple way.
He created around himself a kind of Vaporization Barrier.
Within a certain radius, any being that possessed a soul was subjected to such intense compression that its spiritual structure collapsed—and the body evaporated as a consequence.
It was a brutal method.
But efficient.
With time, he learned to shape that pressure.
Instead of releasing it in a spherical, constant flow, he began compressing and structuring it into a defined form: the so-called Black Box.
The Black Box was not a conventional barrier.
It was an area of absolute spiritual imposition, with an estimated range between 4,700 and 4,800 km². Inside it, the effects of the Vaporization Barrier were replicated—but with far greater force and pressure, varying according to Akoto's will.
It was, essentially, a Domain without relying on the traditional rules of Domain Expansion.
And even so, he barely used it.
His obsessive focus had always been the refinement of the internal use of the fundamental forces. He believed that fully mastering the pillars of the universe was the path to absolute supremacy.
Now, reflecting more calmly, he recognized the mistake.
Neglecting the external domain had been foolish.
The two modes were not opposites—
They were complementary.
The internal use demanded fine control, precision, and physical endurance.
The external use strengthened his presence and body, expanded perception, crushed interference, and stabilized the surrounding environment.
Akoto stopped for a moment.
He had tried to master the universe by beginning with the core of matter.
But perhaps he should begin with his own soul expanded to its fullest.
If he truly wished to become the Strongest, he could not train only half of his power.
He needed to master both domains.
Internal.
And External.
"I need to improve my combat and analytical capacity… there are still flaws."
Akoto murmured to himself as he climbed the broken steps of the arena. His expression was calm, but his mind replayed every second of the confrontation. There had been moments when he was pressured by the numerical advantage. Instants when four simultaneous attacks had nearly forced him to rely on instinct rather than a calculated decision.
If he had missed the timing by half a second…
If he had underestimated their coordination…
If his instincts had not been so refined…
He could have died.
That realization did not frighten him.
But it bothered him.
"Those black flashes… and the veil…"
He was referring to the anomalous flickers that appeared when his forces collided at high intensity—dark distortions that seemed to swallow light for fractions of a second. And also the unstable veil that formed when Spiritual Pressure interacted with Tengen's barrier.
Perhaps there was something there beyond what he understood.
An intermediate application between internal and external use.
A hybrid state.
"Maybe I can do something with that."
Not as a casual remark.
But as a goal.
When he stepped into the stands, the silence was absolute.
No whispers.
No audible breathing.
The atmosphere was heavy—not with energy, but with disbelief.
Tenzo Abe stood completely motionless, his posture stiff like a poorly carved statue. His mouth remained open, nearly touching the floor, his eyes still trying to process what they had just witnessed.
Naoto and Satsugi also couldn't hide their shock. Both stood frozen, eyes wide and fixed on Akoto as if they were staring at something that should not exist. It wasn't just power they had seen—
It was the collapse of an entire paradigm.
Kamikake, on the other hand, showed no astonishment.
His gaze was sharp.
Severe.
And filled with a dense, almost tangible hatred. Unlike the others, he wasn't impressed—he felt threatened. What Akoto represented made many established structures of power obsolete.
Noriaki was the most stunned of them all.
He didn't look afraid.
He looked… displaced.
Like someone who had just witnessed the birth of something that would change the very history of jujutsu.
For everyone there, that battle had been impossible.
A single individual against four promising heirs—each representing powerful lineages, refined techniques, and years of training.
And yet, it had not been an even fight.
It had been unilateral.
And the most disturbing part was not the victory.
It was the technique.
No one there understood what had been used.
It wasn't a Domain Expansion.
It wasn't a conventional cursed technique.
It wasn't standard reversal.
It was something outside the system.
Akoto stopped in front of Tengen.
His tone was respectful, but direct.
"Tengen-sama, if we're finished… let's return." A brief pause. "I need to train."
...
Ten days had passed since the Imperial Assembly.
The return to the temple had been normal. Akoto and Tengen talked about various things along the way, while Ashiya and his father occasionally added their opinions to the discussion.
When they arrived at the temple, Akoto isolated himself with Tengen's permission. During those ten days, he immersed himself completely in training.
And it was during those days that he encountered a difficulty he had not expected.
Executing the Internal Domain and the External Domain of Soul Manifestation simultaneously was absurdly more complex than he had imagined.
If he had to compare it to something, it was like trying to write with both hands at the same time… while being dyslexic.
The Internal Domain required absolute introspection—concentration, constant calculations, and millimetric control over the Four Fundamental Forces.
The External Domain operated in the opposite direction.
It was Release and Imposition.
Spiritual Pressure was not something adjusted through numerical increments; it was something that expanded like a compressed sun trying to be born into the world. The more Akoto released it, the more his presence distorted the environment around him.
The problem was that, although the innate technique functioned as a continuous lapse, the two modes were essentially opposing lapses.
The Internal contracted.
The External expanded.
One demanded the absolute power of the soul to manipulate the invisible foundations of the universe.
The other demanded that the soul roar and crush the space around it.
When he tried to use both at the same time, something fell out of sync.
"Perhaps… I should try another approach…"
Akoto's voice came out low, almost dissolving into the silence of the room.
He slowly uncrossed his legs and closed his eyes, allowing his breathing to slow.
If he could not force harmony between contraction and expansion, then perhaps he needed to find it at the most basic point: the neutral state of the soul itself.
The stone beneath him was cold.
He began to feel the core of Soul Manifestation—not as Internal or External, but as origin.
He did not expand.
He did not contract.
He simply observed.
Knock! Knock!
The sound of wood echoed sharply through the room.
Akoto opened his eyes, the concentration dissipating like mist.
"Hm?" He sighed, already recognizing the presence even before feeling it. "Master Tengen… what do you want?"
The door slid open softly.
Tengen entered without hurry. Her steps were light, but there was something different about them this time.
She did not position herself in front of him.
She did not assume the posture of a teacher.
She did not sit.
She remained standing.
"Akoto… your pursuit of power back then…" She paused slightly, as if choosing her words with extreme care. "I recognized the look in each of their eyes at that moment…"
Akoto remained still.
"And?" He opened his eyes slightly.
"Fear."
The word fell heavily.
"The fear of the existence of someone that strong. It won't be long before they take measures to prevent your rise toward your goal."
The silence that followed was denser than any Spiritual Pressure Akoto had ever released.
He opened his mouth to respond—to say it didn't matter, that he would crush any obstacle—but the words didn't come.
Because he knew.
He knew that this was not just an analysis from Tengen.
It was concern.
To the jujutsu world, he was a growing anomaly.
But to her… he was her son.
She had given him shelter when he had nothing.
Food when he had no strength.
Guidance when he knew nothing.
To say "don't worry" would be the same as ignoring the feeling that moved Tengen.
"I would hate to tell you how you should live," Tengen continued, her voice softer—but extremely fragile. "And I would also hate to say that you need to be careful."
Akoto felt something vibrate inside his chest.
It was his soul.
"As a jujutsu sorcerer, I know the dangers we face. I know the duty we carry." She took a deep breath. "But as a mother…"
Akoto's fingers tightened against the fabric of the kimono over his legs. The slight tremor in his hands did not come from physical exhaustion.
It came from something he still did not know how to name.
"Akoto… just promise me one thing."
He raised his head, but did not turn around.
"Even if others try to tell you how the strong should live… don't listen to them. Not a single one of them." She stepped closer, placing her hand on his back. The touch was warm. Real. "Live your life however you want. The way the strong do."
A pause.
"Become the strongest… please."
"Become the strongest."
In that moment, Akoto understood.
It wasn't a demand.It wasn't ambition being projected onto him.
It was the way she found to say: survive. Come back alive.
For someone who had always pursued the pinnacle as an absolute goal, those words took on a different meaning.
Love was not weakness.
It was an anchor.
It was the reason someone would want to return after winning.
'Love… is necessary.'
Akoto had once considered emotions to be possible distractions. Bonds created vulnerabilities. Vulnerabilities could be exploited.
But perhaps he had been analyzing it incompletely.
If the Internal Domain demanded contraction…
And the External Domain demanded expansion…
Then what was love?
A soul that strengthens within itself… and extends outward to protect something beyond it.
Perhaps the answer was accepting that his soul did not need to exist only to crush.
It needed purpose.
Akoto took a deep breath.
"Yes… mother."