There were many patches of woods around the Kurama clan's residence, some with thick trees while some sparse.
Rei stood in one of such places with sparse trees around him, this was a place where Rei usually trained. Since it was fall leaves fell from the trees and were carried around by gusts of wind.
Rei took out a sword hanging on his back, he had received it from Sakumo Hatake since he usually trained with a wooden one, it was a short bladed tanto similar to Sakumo's White light chakra saber.
As the wind blew through his black hairs he performed some hand seals and took a stance with his sword.
*Genjutsu, Demonic Illusions 100 shuriken*
Almost 7 months had passed since he started training his genjutsu and he had mastered both the chakra shape Manipulation and Yin release Nature transformation to some extent within that time. This made him qualified enough to learn the basic genjutsu scrolls he had.
There were multiple factors involved in casting a genjutsu, first off one needed enough chakra shape manipulation and Nature transformation abilities which would determine the range of casting the genjutsu.
How far one's chakra could travel without losing the Yin release nature transformation would determine its effective range.
Secondly the complexity and effective time of the genjutsu would depend upon the quality of the nature of transformation and the user's chakra volume.
Third was intelligence and talent of the user, depending on the situation the genjutsu is used in it could be very effective or just a waste of chakra, since the moment the victim realised they were in a genjutsu they would try to release it.
The affinity for Yin release and the spiritual energy of the user can also heavily determine the effects of the genjutsu cast.
And the speed of casting genjutsu, which would depend upon the experience of the user, was also very important.
Currently Rei could easily use basic E rank genjutsu a few times, although he was pretty good with his chakra control and Yin release transformation, enough for him to use D rank genjutsu, he severely lacked the chakra for casting such a higher level jutsu. He could probably use one D rank jutsu but then he would have no chakra left to do anything else.
So even Rei who didn't lack intelligence and Yin release affinity needed more chakra volume and experience to become an expert in genjutsu.
Demonic Illusions 100 shuriken technique was a genjutsu Rei derived from the false surrounding techniques which created a fake environment around the victim to confuse them.
Although he already had many other advanced variations in mind he lacked the chakra to practice them.
And since he lacked an opponent to use his jutsu on, he created this one to both practice his genjutsu as well as his reaction speed and Kenjutsu.
*swoosh*
As soon as he performed the hand signs and cast the genjutsu on himself a shuriken was thrown towards him from the foliage.
Tightening his grip on his blade he adjusted his feet slightly and cut the shuriken in half as soon as it entered his attack range.
The shuriken disappeared slowly as if it dissolved in midair as soon as it was cut.
Once the victim interacted with an illusion they would know if it was an illusion depending on the strength of jutsu, they could easily break out of this simple jutsu if they tried but imagine suddenly being surrounded by hundreds of these shuriken it would definitely be confusing and could also prove to be fatal depending on the situation.
*Swoosh*
Before Rei could move his sword another shuriken was thrown towards his back.
His body moved slightly as the shuriken passed by his back.
*swoosh* *swoosh* *swoosh*
While Rei dodged, multiple shuriken continued to attack him and he either dodged or cut them with his sword.
As time passed the speed and the number of shuriken thrown towards him also increased.
*swoosh*
While he was busy cutting one, five more would reach him, as time passed more than 10 shuriken closed in on him blocking his escape paths and leaving him no place to dodge.
Left with no choice he bent his legs and jumped in the air reaching as high as 5 meters more than twice height.
But there was no room for him to relax as a dozen more shuriken had already surrounded him midair.
With his head towards the ground Rei took in the position of the shuriken and swung his sword as he rotated his body.
*swoosh**swoosh**swoosh*
*thud*
Rei landed on the ground and smiled as looked at his perfectly fine body.
It was perfect, he had cut through dozens of shuriken almost at the same time and had managed to dodge the rest.
How could Rei not be happy, in the past few months that he had been practicing this jutsu, this was the first time he had achieved such a feat.
He could hardly survive through the first dozen shuriken when he had just started using this jutsu and would have to feel the pain of remaining shuriken striking him until he lost his consciousness from pain and the shock on his spiritual energy.
"As they say Pain really is the best teacher."
But he had never released the jutsu on his own because the more pain he felt the more determined he became to pass through this jutsu.
Rei wiped his sweat and smiled as looked at dozens of leaves that were cut in half due to his sword.
"I think it's time to increase the numbers."
As the number of shuriken used increased the complexity of the jutsu would also increase, with this he could improve his genjutsu skills as well.
After some rest Rei smiled as he kneaded his chakra and performed the jutsu with an increased number of shuriken.
As 100 became 150 the drain on his chakra also increased.
Now all he had to do was survive through the jutsu's duration.
...
A mentally and physically tired Rei returned home with heavy steps after his training.
He had failed to pass through the 150 shuriken jutsu and multiple times at that.
Although there were no physical wounds he had felt the pain of all the shuriken he had failed to dodge stab him.
As he walked he reviewed the training in his mind devised ways to move more effectively.
"Rei Kurama"
While he was walking a sudden voice from behind startled him.
Rei turned around as swiftly as possible his right hand reaching for his blade hos eyes emanating a faint bloodlust.
The man before him wore a black and grey ninja outfit with a dog mask on his face.
He was an anbu member, a force under the direct control of the Hokage.
Before Rei's hand reached his sword the anbu moved fast and distanced himself from Rei.
"Calm down I am here on the orders of the third Hokage."
The anbu spoke with his hands held forward trying to ease Rei, he was surprised as he had not expected the kid to react like this at all. What surprised the anbu more was the speed at which Rei reacted and the faint bloodlust emanating from him.
"What business does the Lord Hokage have with me for you to suddenly appear like this."
Rei spoke respectfully with the blade now full unseathed in his hands.
"Forgive me for startling you like that but Lord third has asked for your presence in his office." The man spoke as he admitted his mistake but his tone was rather plain liek he wasn't sorry at all.
"I will be there.."
Rei nodded as he seathed his sword and headed inside.
".. in a while." His voice continued from inside as he shut the door behind him.
The anbu looked at the closed door with a surprised expression hidden behind his mask.
'Does this kid not know what a Hokage is?'
He shook his head without dwelling on it too much and disappeared from there with a hand seal.
------
AN
1. If you could make a genjutsu what would it be? (I could use them if i find them interesting)
2. Are there any interesting Konoha members slightly older than Kakashi and not in his batch?(alive during this time)
3. Love interest vote: OC female Uchiha vs Hatake Kakashi(JK though there will hardly be romance if any).