While Izayoi and Hinata were out shopping with Hanabi, a huge waterfall beneath the South He River near the Uchiha Clan residence produced a great deal of noise.
If a member of the Hyuga Clan were to open their Byakugan here, they would notice a cave hidden beneath the waterfall.
Inside the cave, loud crashing sounds echoed, though they were drowned out by the roar of the waterfall.
If one touched the surrounding cave walls, they could also feel occasional tremors.
Blue light tore through the darkness inside the cave.
A blue-white spherical shape, much like an inflated balloon, rapidly expanded.
Soon, the basketball-sized energy sphere flew deeper into the darkness.
Boom—
With a deafening explosion, shockwaves roared, and sand and debris scattered into the air.
The dust didn't escape the cave, as the gust of wind quickly blew it away.
Once everything settled, another energy sphere appeared and flew deeper into the cave, triggering a violent explosion once again.
The cave had been formed by such energy spheres.
"The core is complete. After this, I can start producing smaller balls inside," Izayoi's shadow clone muttered as it appeared at the cave's illuminated entrance, sorting through the results of today's training.
Izayoi had already mastered the basics of the ultra-hurricane chain ball, a technique from the TV anime. This was essentially transforming the Rasengan into a size just under the Great Ball Rasengan.
It had taken Izayoi two full years to achieve this.
He finally understood why Naruto Uzumaki had needed to train for three years and use shadow clones to help with his Rasengan.
Izayoi thought back to the time when Naruto couldn't even perform the basic Rasengan with one hand. Trying to scale it up to the size of the Great Ball Rasengan and maintain balance without the chakra detonating was nearly impossible.
Even Izayoi himself had spent two years just to reach this level of chakra control.
If it were just about gathering chakra into a large mass, that wouldn't have been too hard.
The true difficulty was getting all that chakra to rotate at super high speeds.
That was truly hell-level difficulty.
The Rasengan was already a top-tier shape transformation, with a difficulty rating of A.
The Great Ball Rasengan was somewhere between A and S rank.
No wonder S-rank jutsu were referred to as techniques that could not be mastered even with the greatest effort or talent.
Just creating such a large energy ball was already so difficult.
Trying to produce five smaller balls inside it would be as challenging as Naruto's refinement of the Wind Release: Rasengan.
Then, injecting five different elemental nature transformations into those five small balls would make anyone's head ache just thinking about it.
If he succeeded, the power of the technique was secondary—its learning difficulty would exceed S-rank, reaching an SS-rank level.
Even Asura Otsutsuki couldn't pull off such a feat.
But that was Izayoi's target.
He had greater potential than Asura, who needed power from Otsutsuki Hagoromo to achieve such feats.
If his purple-level chakra control wasn't enough, he could always raise it to gold-level chakra control.
Once he developed the Ultra-Hurricane Chain Ball, he would be able to defeat any opponent just like Naruto, with a single move.
No matter the enemy, he would handle them with a Rasengan.
Sitting cross-legged before the waterfall, Izayoi's shadow clone continued to gather chakra with both hands, forming another basketball-sized energy sphere. This time, he didn't throw it out.
He continued to cultivate until all his chakra was depleted, and then the shadow clone dissolved into a puff of white mist.
The fatigue and experience were fed back into Izayoi's main body.
Izayoi, who was feeding Hanabi rice dumplings at the time, merely raised an eyebrow before returning to normal.
Even Hinata, who had been secretly watching him, didn't notice any change.
Since mastering the Rasengan and attempting to develop the Ultra-Hurricane Chain Ball, Izayoi had rarely practiced with his main body.
He usually sent shadow clones into the cave to train, and even when he did practice with his main body, it was just to accompany Hinata at the neglected training ground.
He was quite sure that he had been under surveillance by Hiruzen Sarutobi's crystal-clear vision technique.
Over the past two years, Izayoi had fought against Sasuke Uchiha once every couple of weeks.
He couldn't believe that his no-holds-barred matches with Sasuke hadn't caught the attention of Hiruzen Sarutobi.
After all, Itachi Uchiha had reported to him before leaving the village, and then threatened Danzo Shimura.
If not for his fear of the Byakugan being exposed, Izayoi almost couldn't resist turning on his Byakugan to check if there were any Anbu around.
Having shadow clones train meant that Izayoi could easily control their chakra amounts, and the fatigue feedback was kept within an acceptable range.
Once Hanabi finished eating the rice dumplings, Izayoi played with her, letting her experience the thrill of tree climbing and high-speed movement.
Though Hanabi hadn't started training yet, she had already seen Hinata and Neji's fight, as well as Hinata and Izayoi's training and battles.
Like in the original story, she began to wish she could become as kind and powerful as her sister.
Thus, Hanabi, despite being a little greedy, didn't enjoy playing with children her own age. Instead, she preferred having Izayoi carry her around, running across rooftops to feel the thrill of a "roller coaster."
When the time came for her to start extracting chakra and training, she would surely become even more attached to him.
"Onī-chan, bye-bye!" Hanabi waved as she clung to Izayoi.
"Bye-bye."
After spending the whole afternoon playing with Hanabi, Izayoi smiled and waved goodbye to the clingy little sister-in-law.
Then, instead of returning home, he went to the market to buy some ingredients. Using the Body Flicker Technique, he arrived at the Uchiha Clan's huge, empty residence, where only Sasuke Uchiha was present.
"You're here," Sasuke greeted, his face full of battle spirit as he saw Izayoi carrying two bags of ingredients.
"Let's eat first, then we'll fight. It's good to rest a bit," Izayoi said with a smile.
"Alright," Sasuke agreed.
Later that night, the two were eating hot pot together in the yard.
When the night grew late and the village was quiet, two small figures darted through the Uchiha Clan's grounds like arrows and entered the nearby forest.
Bang bang bang...
Whoosh whoosh whoosh...
The sounds of collisions, heavy objects falling, and projectiles slicing through the air echoed in the forest.
Boom—
Soon, an explosion rang out, followed by red flames blooming in the night.
However, the flames quickly died out.
Half an hour later, the two small figures emerged from the forest.
Under the moonlight, Izayoi and Sasuke formed a stark contrast.
Izayoi's clothes were pristine, as if untouched by a speck of dirt.
Sasuke, on the other hand, wore torn clothes, his body covered in burn marks. His exposed skin still bore faint scars.
Despite his exhaustion, the young man's eyes gleamed with excitement, clearly having gained something from their training.
"I won again," Izayoi said, grinning at Sasuke. "As per our agreement, I want to check out your clan's ninjutsu library."
"Do what you want. It's just a few things anyway," Sasuke replied indifferently.
After the Uchiha Clan was destroyed, the bodies of the clan members were buried by the village.
As compensation, all the scrolls were taken away.
Even the family's inheritance had been reduced to some low-level jutsu scrolls.
Sasuke had asked the Third Hokage about the high-level jutsu scrolls, and it turned out that they had been taken by Itachi Uchiha before he left.
Sasuke didn't mind that the village had taken the family's scrolls.
After all, the Third Hokage had promised that once Sasuke became a ninja and grew strong enough to take over the Uchiha Clan, he could request the village to return the deeds and the ninjutsu scrolls.
Sasuke wasn't yet strong enough to guard those things.
Izayoi knew that Hiruzen Sarutobi wasn't lying.
Apart from secret techniques like Izanagi and Izanami, the Uchiha Clan's jutsu scrolls weren't really worth coveting.
Compared to the powerful Uchiha warriors, these scrolls weren't even worth the trouble.
Just like the inheritance left by Izayoi's parents.
However, the Uchiha Clan's ninjutsu library was still very useful to Izayoi.
He had an exceptional grasp of shape transformation but almost zero nature transformation.
Training in the five nature releases would significantly improve his nature transformation skills.
If he wanted to perfect the Ultra-Hurricane Chain Ball, he would need to master five nature transformations that could be integrated with it.
For Wind Release, Izayoi could learn from Naruto Uzumaki in the original story, but for the other four nature transformations, he would have to either train on his own or consult a Jonin for guidance after graduation.
Of course, there was another shortcut—one that didn't require any training but would give him the ultimate nature transformations.
That was... awakening the Rinnegan or the Transmigration Eyes!