Half a month passed quickly.
Danzo had been released a week ago, but after the harsh lesson he received, he had noticeably restrained himself. For now, he had not caused trouble for Uchiha Kiyo.
However, Kiyo knew that Danzo was merely lying in wait, planning something in the shadows.
In the past two weeks, Uchiha Kiyo had led a fulfilling life.
Every day, he focused on training, refining his techniques, and experimenting with his secret Clone Art.
At night, he buried himself in research, going through countless documents on Chakra, most of which revolved around its refining principles.
Finally, he found hope—evidence that a clone could extract Chakra on its own.
From the data, he came across an in-depth description of spiritual energy.
It was defined as energy refined through repeated training and accumulated experiences.
That meant spiritual energy could be cultivated and increased through exercise and personal experience.
To test this, Uchiha Kiyo tried various exercises, and indeed, his spiritual energy grew.
However, the increase was too slow.
This frustrated him until he stumbled upon a surprising discovery—when he depleted a large amount of Chakra, his mental energy also decreased.
But when he exercised while his mental energy was low, the regeneration speed was significantly faster!
It wasn't that the generation of spiritual energy increased—it was its recovery speed.
He realized that once his spiritual energy reached a certain threshold, the recovery rate slowed down.
With this in mind, Uchiha Kiyo decided to focus on exercise as a method to refine and recover his spiritual energy.
He spent several days perfecting the theory, and in principle, it seemed flawless.
But when he attempted to apply it practically, he encountered a major problem.
His clones had no soul.
This was a devastating setback.
The relationship between spiritual energy and the soul was incredibly complex.
Spiritual energy wasn't simply an offshoot of the soul, but it was undeniably linked to it.
Through analysis, Uchiha Kiyo concluded that spiritual energy acted as a sort of authentication system, a bridge that connected a ninja's Chakra to their soul, allowing them to control it.
Without a soul, it was impossible to generate spiritual energy.
"Does this mean my method failed?"
"No, there must be a solution."
"If my clones lack a soul… I need to find something that can replace it."
But what could possibly substitute for a soul?
For a long time, Uchiha Kiyo was lost in thought.
Then, an idea struck him.
"Maybe… I'm overcomplicating this."
He considered the foundation of his Clone Art—what made it work in the first place?
The Five Elements Seal and the Shadow Clone Technique.
The answer was within these two.
And then it clicked—
Shadow Clones!
If a shadow clone retained the user's thoughts, experiences, and even a portion of their Chakra, then perhaps it could substitute for a soul.
But how?
Should he seal it inside the brain? No, that wouldn't work.
The soul wasn't located in the head, it was integrated throughout the entire body.
Even Orochimaru, when his soul was devoured by the Reaper Death Seal, lost entire sections of his being based on the limbs affected.
That meant a simple placement wouldn't be enough.
So how could he make the shadow clone take on the role of a soul?
He needed to rethink his approach.
Spiritual energy acts as both authentication and a connection.
Could he use that function?
Uchiha Kiyo felt exhausted from all the thinking. He made a mental note to rest once he figured this out.
"So… what if I use the spiritual energy inside a shadow clone's Chakra as a transfer station?
If I do that, the clone would be directly connected to my soul… which means it should be able to generate its own Chakra."
Perhaps the reason this hadn't worked before was that the spiritual energy within Chakra was suppressed when merged with physical energy.
If he extracted it separately and reintroduced it, would the connection form?
There was only one way to find out.
Unfortunately, he lacked an immediate test subject.
His previous experiment had been performed on a clone he stationed in the Land of Rain. However, this method required direct extraction of spiritual energy, and he had no idea how much would be needed.
Bringing the clone back from the Land of Rain wasn't an option—it didn't have enough Chakra reserves left for something this risky.
Instead, Uchiha Kiyo separated a large portion of his own Chakra, extracting the spiritual energy and wrapping it in an outer layer of Chakra to prevent dissipation.
When the spiritual energy reached a certain threshold, he felt something.
A connection.
"This… it's working."
When the amount of spiritual energy increased past a certain point, it directly linked back to his soul.
And the more he increased it, the farther the connection could reach.
"This explains mental perception…"
Perhaps this was how Shadow Clone memory transfer worked—through the spiritual energy connection.
However, he had no time to study that now. Perfecting his Clone Secret Art took priority.
Uchiha Kiyo ran multiple experiments, confirming that as the distance increased, the required amount of spiritual energy rose—but not as drastically as he feared.
It also seemed that this connection was conceptual rather than physical, meaning space didn't heavily impact it.
In theory, this could allow for ultra-long-distance perception.
However, there was a downside.
Spiritual energy, when existing independently, dissipated too quickly.
To maintain it over long distances, he would need to constantly extract more spiritual energy from his Chakra, but his control over that process was limited.
This made it hard to expand the range of perception.
There was another method—wrapping the spiritual energy in Chakra to stabilize it.
But this required precise Chakra control and a huge energy investment.
For the sake of experimentation, Uchiha Kiyo entered the Forest of Death and hunted down an ape-like beast.
Bringing its corpse home, he applied the same Clone Secret Art process on it, turning it into a test subject.
Everything appeared normal—the body was fully functional, with all necessary enzyme secretions present.
Now, it was time to test his theory.
Summoning a shadow clone, Uchiha Kiyo sealed it inside the experimental clone using the Five Elements Seal.
Once the process was complete, the shadow clone took control of the body, using its Chakra to extract spiritual energy.
It then distributed the spiritual energy throughout the clone's body.
The test subject clone began moving—performing push-ups, punches, kicks—simulating intense training.
And then—
A trace of spiritual energy emerged.
"It worked!"
But something was different.
Instead of accumulating in the mind, the newly generated spiritual energy spread throughout the body.
Uchiha Kiyo was ecstatic—but then he noticed something alarming.
The spiritual energy was dissipating before he could refine it further.
Reacting quickly, he ordered the shadow clone to extract physical energy and immediately repeat the exercise.
The moment spiritual energy was generated, the shadow clone fused it with physical energy.
A new type of Chakra emerged—distinctly different from his original Chakra.
More importantly… it didn't dissipate.
And under the control of the shadow clone, it began circulating naturally within the clone's body.
JOIN MY PATREON TO READ ADVANCE 125+ CHAPTERS
patreon.com/HACKDWORLD