Kaida was shocked by that. He had very good chakra control, so if he was unable to deduce that he was in a genjutsu, then normal Genin and even some Chunin didn't stand a chance of knowing about it.
Also, just the implication of appearing behind the back of the enemy without them noticing was too powerful. He was slowly understanding how truly powerful genjutsu was.
But just to be on the safe side, Kaida disrupted his chakra. As he had guessed, Shisui disappeared from his back and appeared sitting in a chair in the garden.
Seeing Kaida had come out of the genjutsu, Shisui stood up and said, "At least you have a good brain. Now let me first remind you of the basics of genjutsu. Genjutsu is like a mental trick; in this, we're messing with someone's mind. Here's how it works in ninja terms:
Chakra Manipulation: Ninjas use chakra, which is their inner energy, to cast genjutsu. They focus their chakra and project it outward to create illusions. It's like using your mental strength to create a powerful illusion that affects someone else's mind.
Sensory Deception: Imagine you're seeing something, hearing something, or feeling something, but it's not real. That's what genjutsu does. It messes with your senses, making you perceive things that aren't happening. It's like a really convincing dream that you can't wake up from.
Mind Games: When you're caught in genjutsu, your brain believes the illusion is real. So even though nothing is happening, your body reacts as if it is. It's like your mind is playing tricks on you, and you can't tell what's real and what's not.
Chakra Influence: Advanced genjutsu techniques can mess with your chakra directly. Chakra is your inner energy, and if someone messes with it, it can affect you mentally. It's like someone tampering with the signals in your brain, making you see things that aren't there or feel things that aren't real.
Now, how do you think one can attack another's mind?"
"By somehow passing our chakra into their brain and trying to control their thoughts," Kaida replied, though he was not sure.
"You are correct in some ways, but if you go with this approach, you will never be able to use genjutsu.
There is a key point you are missing here. Can you guess what it is?" Shisui asked. He could have directly told him the process of using genjutsu, but that would have been the worst way to teach someone.
If you just tell them everything, then they are not learning anything; they're just memorizing what has already been discovered and fed to them.
But what Shisui was doing was making Kaida think about how he could achieve his goal and helping him when something would take a large amount of time or be extremely difficult to find on his own.
Kaida, after thinking for some time, said, "Since our chakra is poisonous to others, if we send it to another's mind, it will likely damage their brain rather than putting them in genjutsu.
So simply sending our chakra is not an option, as everyone can feel that, and their bodies will naturally reject that chakra. It is not possible to just send our chakra and alter their thoughts.
This means we have to modify our chakra to make it useful for genjutsu."
"Very good! I knew you were talented," Shisui said, laughing, and then continued, "Kaida, as you know, chakra is made up of two types of energy: physical and spiritual energy, but that is just the basics everyone knows.
We ninjas have classified this energy as yin and yang; yin is the spiritual part, and yang is the physical one.
For casting genjutsu, you only have to use the spiritual part of your chakra, which is Yin Release."
"But if the chakra is made up of physical and spiritual power together, how will it retain its state if we break it down into its components? If it can remain in its components, then strong civilians should be able to become at least… pseudo-ninja or something."
"What is this pseudo-ninja thing? You have a creative mind. Yes, your deduction is correct; you can completely break chakra into its components.
But for genjutsu, you have to make your chakra consist mostly of your spiritual energy while using physical energy as little as possible."
"So, we have to find a perfect ratio for this?" Kaida asked.
"No, there is no perfect ratio for this. When you are barely able to use your chakra in a ratio of 85:15, then you will be able to use rudimentary genjutsu.
At this stage, even a genin can discern that they are under some form of genjutsu because even with just 15 percent of your physical chakra, the enemy's brain will take some damage, and the genjutsu will be very unstable."
"So, is this yang chakra responsible for all the offensive power of the jutsu?" Kaida asked after listening that Yang Release is what damages the enemy's brain.
"No, you are getting it all wrong. It is not chakra that is responsible for damage; it is your intent that does the damage.
When you use fire or lightning chakra around you, you will not get injured by the chakra itself. Its effects, like fire or lightning, can damage you, but your chakra will do you no harm.
That is because you don't want it to. In the same way, yin and yang releases have different intents.
You can use Yang Release to enhance your strength as well as for medical ninjutsu. The same goes for Yin Release; you can use it for genjutsu as well as shadow techniques, which the Nara clan uses.
And not just these, there are various other implications of this. More Yin chakra in your normal jutsu even allows you to somewhat control your jutsu even after you release it, but that's high-level stuff. For now, let's focus on the basics, okay?"
Kaida nodded his head, thinking it was the right decision to join the Uchiha compound.
"Now activate your Sharingan and see how I divide my normal chakra into yin and yang," Shisui said while taking chakra out of his hand and making a ball out of it.
It eerily resembled one of the famous jutsu of the Naruto series.
Kaida, though shocked, understood that it was easy to do with enough chakra control and practice.
Kaida activated his Sharingan as Shisui said. Seeing this, Shisui started manipulating his chakra, and it began to get divided into two parts: one being hot and bright, while the other was cold and dark. They started revolving around each other.
"So I have to do that?" Kaida asked, finding the task quite difficult.
"Hahaha, no, you don't have to do this. You technically have to do it, but you don't have to make it as showy; you just have to do this inside your body."
"Oh! Okay." Then Kaida began concentrating on the difference between Yin and Yang chakra.
After five minutes, Shisui stopped the magic show and said, "Now, how do you think the Sharingan helps us in genjutsu?" Shisui asked again.
"Maybe the Sharingan helps us separate the yin chakra and make it more stable, or helps in projecting it out of our body."