Konoha, reported by the Fourth Hokage at the start.

Chapter 97 Illusion - Sensory Deprivation Technique

What is the principle behind illusion?

By integrating genjutsu chakra into another person's body, the flow of genjutsu chakra into that person's brain can influence their mind, causing the enemy to fall into a genjutsu trap.

Essentially, it involves using genjutsu chakra to input or induce false information into another person's brain, thereby confusing the brain's cognition and, consequently, the physical sensations transmitted from the brain.

The key here lies in the input and output of information.

The input of information allows the illusion to invade.

The output of information makes all the perceptions of people in the illusion become real.

It can be said that most illusions, whether visual, tactile, or auditory, start from the input and output of information.

The same applies to the art of darkness.

However, the art of darkness is different from other illusions.

Other illusions that deprive someone of sight do so by inputting information into the brain, causing the brain to generate the information response of "not being able to see".

The primary target of its effects is the brain.

No, it was the Dark Travel Technique. Li Yao clearly sensed that the Dark Travel Technique chakra was stationary in his eyes, directly severing the neural pathways that transmitted all light signals received by the eyes back to the brain.

A physical severance.

The two wandering ninjas' eyes are actually fine now; they can see anything.

However, because the signals from the eyes to see objects do not reach the brain, the signals transmitted by their brains are darkness, and their vision is also darkness.

This is the principle behind the Dark Walk technique. Compared to other illusions that disrupt the brain's perception, it is simple, brutal, and highly effective.

Compared to the disruption of the brain caused by genjutsu chakra in ordinary people, this simple and brutal genjutsu that directly cuts off the signal transmission path of a certain organ seems even more difficult to dispel.

Thinking of this, Li Yao took the initiative to remove the black iron chains from the bodies of the two ninjas who had been affected by the Dark Travel Technique.

After their chakra flow was restored, he then deliberately disrupted the chakra flow within their bodies.

"It's no use!!!"

Despite having anticipated it, Li Yao was still surprised by the power of the Dark Travel Technique, or rather, amazed by the genius idea of ​​the Second Hokage, Tobirama.

It goes without saying that he truly is a man who has spent his entire life targeting the Uchiha clan.

Strictly speaking, the Dark Travel Technique is not an illusion technique at all; it is merely a technique similar to a nerve signal severing technique that utilizes the special properties of illusion chakra.

No wonder those afflicted by the Dark Travel Technique retain all their senses except for their eyesight, and can also use various ninjutsu.

So that's the principle behind it.

The Second Hokage was quite cunning; he named it "Dark Travel Technique" even though it wasn't a genjutsu.

The unsuspecting enemy, thinking they've been afflicted by a dark magic spell, tries to break free using illusion techniques, only to find they can't. They must be quite desperate.

This is especially true for the Uchiha clan, who are very skilled at dispelling genjutsu.

The art of darkness was their nightmare.

Even the strongest Uchiha clan ninja cannot break free from the Dark Travel Technique if they do not understand its principles.

To dispel the Dark Movement Technique, one only needs to know the exact location around the eyes where the Dark Movement Technique's chakra is acting, and then precisely input chakra to disrupt that portion of the Dark Movement Technique's chakra, thus dispelling the Dark Movement Technique.

It sounds simple, but there aren't many people who can perceive genjutsu chakra so accurately, especially since the genjutsu chakra of the Dark Path Technique is even more illusory, hidden, and difficult to detect. This is why the Dark Path Technique has always been called genjutsu.

In fact... it can indeed be called an illusion, but its principle is different from most illusions.

However, the principle of the Dark Travel Technique did give Li Yao some inspiration.

With a thought, Li Yao manipulated the Dark Travel Technique to envelop the brains of the two wandering ninjas with chakra.

In his perception, the transmission paths of external signals flowing into the brain were very small, so small that Li Yao seemed to see the smallest energy unit of chakra, like rays of light made up of photons, densely covering the brain.

To precisely sever such a dense signal transmission path using Dark Travel Technique chakra is extremely difficult.

Fortunately, Li Yao's absolute control over chakra allowed him to do it.

With a thought, Li Yao used the Darkness Technique to cut off the signal transmission through the eyes, precisely severing all signal pathways to the brain.

In an instant, the brains of the two wandering ninjas seemed to be trapped inside a sphere, unable to receive signals from their sensory cells. They became like vegetable beings, their struggling bodies suddenly quieting down and becoming completely still.

But soon, after only a third of a second, the two began to struggle violently again, shouting for mercy.

"This is……"

Li Yao frowned immediately. The Dark Travel Technique chakra that had imprisoned the brains of the two ninjas was broken by their instinctive chakra bursts.

Genjutsu chakra is used to infiltrate and merge with another person's chakra without being detected. It is illusory and soft like water, and can be easily broken.

This is why someone under the influence of a genjutsu can break free of it by disrupting their own chakra.

Li Yao discovered a weakness in the Dark Travel Technique.

Because it wasn't a genjutsu, the Dark Travel Technique's chakra forcibly severed the two ninjas' brains from receiving all signals. Although their bodies were in a vegetative state, their brains remained conscious, and they were able to make some responses based on their consciousness.

They had just manipulated the chakra in their brains to unleash a burst, thus dispersing the chakra of the Dark Travel Technique and releasing it from their brains.

However... the price seems a bit too high!

They watched as the two wandering ninjas struggled violently for a few moments before foaming at the mouth, rolling their eyes, and finally becoming completely unable to move.

Li Yao's brows relaxed, and he smiled slightly.

Although the two had broken the Dark Travel Technique's chakra blockade on their brains, the sudden burst of chakra in such a vulnerable area as the brain would still affect them.

This has a significant impact.

Now, the two wandering ninjas have been turned into mentally disabled vegetative state patients by their own chakra burst.

"This ninjutsu still has some value."

Li Yao suddenly curled up the corner of his mouth. Especially for ninjas with poor chakra control, once they are hit by the Dark Travel Technique that cuts off the transmission of brain signals, they will be like the two wandering ninjas now. Even if they release the Dark Travel Technique, they will still become idiots and vegetative because they cannot control their chakra bursts.

Even a ninja with precise chakra control would likely need some time to carefully dispel the Dark Travel Technique chakra that shrouds their brain.

This was enough time for Li Yao to kill the enemy.

It can be said that Li Yao developed a trump card ninjutsu by using the Dark Travel Technique, a ninjutsu that can kill him in a critical moment.

So here's the question.

Such a powerful dark-based ninjutsu... why didn't the Second Hokage leave it behind?

A question flashed through Li Yao's mind, and he frowned slightly. The original work did not mention the use of the Dark Travel Technique, but that did not mean it did not exist. Perhaps someone in Konoha knew it?

"Fortunately, I am very sensitive to chakra, and my consciousness that is integrated with chakra rejects any foreign chakra that tries to invade."

"So... there's no need to worry too much."

"So... what should we call him?"

Li Yao tilted his head slightly. It was obviously inappropriate to call this brain-targeting ninjutsu the Dark Travel Technique.

"Since the effect is to turn someone into a vegetable, let's call it... Illusion - Perception Deprivation Technique."

Li Yao chuckled and, like the Second Hokage, resorted to a dirty trick, giving this ninjutsu the name of a genjutsu (illusion technique).

(End of this chapter)