Chapter 20: The Future SS-Rank Ninjutsu

  While Izayoi and Hinata were out strolling through the streets with Hanabi, the scene shifted elsewhere. Near the Uchiha district, by the Naka River, beneath a rge waterfall, y a hidden location. If a Hyūga cn member were present and activated their Byakugan, they would discover a cave concealed behind the curtain of water.

  At this moment, tremendous noises emanated from within the cave, though they were muffled by the roar of the waterfall. Touching the surrounding rock walls, one could feel intermittent vibrations. Inside the cave, blue light tore through the darkness. A blue-white sphere, resembling a water-filled balloon, rapidly swelled. Subsequently, this basketball-sized energy sphere flew into the shadows.

  Boom—

  Accompanied by an explosion, shockwaves roared, and sand and gravel scattered everywhere. The dust cloud didn't even escape the cave before being dispersed by a gust of wind. Once everything settled, another energy sphere formed and flew again into the deeper darkness, setting off another violent explosion. The cave, remarkably, had been carved out by such repeated energy sphere detonations.

  "The core is complete. Next, I can start creating the smaller spheres inside." Izayoi's Shadow Clone appeared at the cave entrance where light filtered in, taking stock of the day's achievements.

  He had mastered the foundation of the anime-original Super Hurricane Sphere Barrage – that is, expanding the Rasengan to a volume just shy of the Great Ball Rasengan. This alone had taken Izayoi a full two years.

  Izayoi finally understood why Naruto Uzumaki, even after three years of training, still needed Shadow Clone assistance to perform the Great Ball Rasengan. For someone who couldn't even manage a one-handed Rasengan initially, expanding it to that size while maintaining stability and preventing the chakra from exploding was practically impossible. Even Izayoi, despite his advantages, took two full years to elevate his chakra control to this level.

  Simply gathering that much chakra into a rge mass wasn't exceedingly difficult. The challenge y in keeping that massive amount of chakra gathered while making it rotate at super high speeds. That was truly hell-level difficulty! After all, the basic Rasengan was already considered the pinnacle of shape transformation, with an A-rank learning difficulty. The Great Ball Rasengan must surely fall somewhere between A-rank and S-rank.

  No wonder S-rank ninjutsu were deemed 'secret techniques' – techniques that even immense effort and supreme talent couldn't guarantee mastery of. If creating just the rge energy sphere was already this difficult, then forming five stable spheres inside it was undoubtedly a challenge comparable to Naruto perfecting the Wind Release: Rasenshuriken. And then, simultaneously infusing those five smaller spheres with five different elemental nature transformations... the difficulty made his head hurt just thinking about it.

  If successful, regardless of the resulting power, the learning difficulty would definitely be above S-rank, likely reaching SS-rank. This was something even Ashura ōtsutsuki couldn't achieve in the filler depiction. Yet, it became Izayoi's goal. His current potential surpassed even Ashura, who needed power bestowed by Hagoromo. If Purple-rank Chakra Control wasn't sufficient, he would simply upgrade the trait to Gold using points. Once he successfully developed the Super Hurricane Sphere Barrage, he could, like Naruto Uzumaki, rely on one signature "Rasengan-style" move to handle almost any situation. No matter the enemy, a 'ball' could solve it.

  Sitting cross-legged before the waterfall, Izayoi's Shadow Clone continued condensing chakra between its hands, forming another basketball-sized energy sphere. This time, however, it didn't throw it. The clone continued practicing until its chakra was depleted, then dispersed into a puff of white mist. The fatigue and experience flowed back to the main body.

  Izayoi, currently feeding Hanabi a sticky rice dumpling, merely raised an eyebrow slightly upon receiving the feedback before returning to normal. Even Hinata, who had been sneakily watching him, didn't notice any change.

  Ever since mastering the Rasengan and attempting to develop the Super Hurricane Sphere Barrage, Izayoi rarely trained with his main body. He let Shadow Clones handle the cave training. When his main body did train, it was usually just accompanying Hinata at the deserted training ground (or more recently, safer locations). He was quite certain that Hiruzen Sarutobi had spied on him using the Crystal Ball Telescope Technique. His regur spars with Sasuke Uchiha over the past two years must have drawn Hiruzen's attention. After all, before leaving Konoha, Itachi had reported to Hiruzen and then threatened Danzo Shimura. If not for the fear of revealing his Byakugan, Izayoi would have been tempted to activate it to scan the surroundings for monitoring ANBU.

  By consistently using Shadow Clones for the intense training, Izayoi had long learned to manage their chakra levels carefully, ensuring the feedback fatigue remained within acceptable limits.

  After Hanabi finished her rice dumplings, Izayoi continued pying with her, carrying her high on his shoulders while using Body Flicker, or demonstrating tree walking and water walking. Although Hanabi hadn't started training yet, having watched Hinata and Neji fight, as well as witnessing Hinata train and spar with Izayoi, she, like her original story counterpart, had developed the desire to become strong and gentle like her older sister. Consequently, apart from being a bit greedy with food, Hanabi didn't much care for pying with peers her age; she preferred having Izayoi take her 'flying over rooftops and scaling walls,' experiencing the thrill akin to a rollercoaster ride. Izayoi anticipated she would become even clingier once she began her own training.

  "Onii-chan, goodbye."

  "Bye-bye."

  Having pyed with Hanabi until dusk, Izayoi smiled and waved goodbye to his clingy little sister-in-w. Then, instead of heading home, he went to the market to buy some groceries and used Body Flicker to travel to the Uchiha compound – vast, empty, and poputed solely by Sasuke Uchiha.

  "You came." Sasuke, who was training in the courtyard, looked up, his eyes filled with fighting spirit as he saw Izayoi arrive carrying two bags.

  "Let's eat first, fight ter. Take a break," Izayoi suggested with a smile.

  "Alright." Sasuke didn't refuse.

  After night fell, the two ate hot pot together on the veranda. Later, in the dead of night, two small figures darted through the compound like arrows, entering a nearby forest.

  Thump, thump, thump...

  Swish, swish, swish...

  The sounds of impacts, heavy objects hitting the ground, and projectiles cutting through the air echoed continuously through the nighttime forest.

  Boom—

  Before long, an explosion rang out, and red fmes bloomed briefly before being quickly extinguished.

  Half an hour ter, the two small figures emerged from the forest. Under the moonlight, the contrast between Izayoi and Sasuke Uchiha was stark. Izayoi's clothes were neat, seemingly untouched by dust. Sasuke, however, was cd in ragged clothes, his body covered in burn marks, with faint scars visible on his exposed skin. Despite his exhaustion, the boy's eyes gleamed brightly, clearly indicating he had gained significant experience.

  "I win again," Izayoi said to Sasuke with a smile. "As per our agreement, I get to check out your family's ninjutsu library."

  "Whatever. There's only a few things left anyway," Sasuke replied dismissively. After the Uchiha cn's destruction, the vilge had buried the bodies, confiscating all scrolls as compensation. Only some low-level elemental ninjutsu scrolls remained in his family home's inheritance. Sasuke had asked the Third Hokage about it; Hiruzen cimed the vilge hadn't touched their advanced ninjutsu scrolls, implying Itachi must have taken them. Sasuke didn't particurly care about the confiscated scrolls, as the Third Hokage had promised him that once he became a ninja and grew strong enough to take charge of the Uchiha cn, he could apply to the vilge to recim the nd deeds and ninjutsu scrolls. Right now, he cked the strength to safeguard those items anyway.

  Izayoi knew Hiruzen was mostly telling the truth. Apart from secret techniques like Izanagi and Izanami, the standard Uchiha ninjutsu scrolls weren't particurly coveted by the vilge leadership, especially when compared to securing the loyalty of a powerful Uchiha survivor. It was simir to how his own parents' modest inheritance had been left untouched.

  However, the remaining scrolls in Sasuke Uchiha's family library were still very useful to Izayoi. His shape transformation skills were extremely high, but his nature transformation proficiency was almost zero. Practicing elemental ninjutsu was the way to improve nature transformation. To perfect the Super Hurricane Sphere Barrage, which he intended to infuse with elements, Izayoi needed mastery over all five basic nature transformations, strong enough to fuse with the technique itself. He could learn Wind Release by referencing Naruto's methods from the original story, but the other four natures would require self-study through practice and comprehending scrolls, or asking his future Jonin instructor for guidance after graduation.

  Of course, there was also the ultimate shortcut to possessing top-tier nature transformation mastery without any training: awakening the Rinnegan or the Tenseigan!