(Sasuke's Point of View)
In the skies of Konoha, blue bolts of lightning arced menacingly across the dense clouds. They didn't leave them though. It was as if their purpose was to create an ominous atmosphere to terrify the masses.
Surprisingly enough though, very few people reacted. In large part, the village was used to this type of weather, especially on the weekends. It was a surprise the first couple of times, but people eventually got used to it when they realized what was actually happening; it was training. The fourth Hokage's wife was training her lightning nature transformation.
After her first husband's death, she seemingly lost any satisfaction she may have had with settling for average jonin-level strength. When it came to lightning training specifically, her methods were normal at first. For the first five years, she mastered every known exercise for lightning. After that, she developed something revolutionary in all of Konoha, a family of techniques that gave her the right to make a separate clan on its alone.
In essence, she redefined storm release. The known technique was invented by Kumo and was used exclusively by them; it combined water and lightning natures. Normally, shinobi wouldn't consider taking the name of another technique; they would just name their new one something else. It was a matter of pride.
When Mikoto's techniques became known though. The shinobi council pushed to have it take the name of storm release despite tradition. Eventually, Mikoto compromised and decided on storm style. Why?
Her techniques involved creating the conditions for a natural thunderstorm and channeling its power into a variety of jutsu. By using the storm's natural power, any limitations derived from her chakra pool became irrelevant. What made it even more efficient was that any energy she pulled from the storm was eventually, automatically directed back up as ground to cloud lightning using a stationary lightning release barrier ninjutsu. That said, this was all still lightning release and therefore, she decided to use 'style' in the name instead.
Now, Sasuke was learning just how frightening this technique could be.
Controlling concentrated bolts of lightning, Mikoto formed snake-shaped bolts that chased Sasuke at a speed just outside of his comfort zone. She was using more personal chakra than the technique normally required to keep the bolts from moving at their natural speeds. If they were, Sasuke wouldn't even be able to perceive how he died. Hell, Itachi needed his Susanoo to take the hits to stay competitive. Even he wasn't fast enough to dodge natural lightning bolts. He was getting close though.
'What the hell!? Since when could mom do this!?' The young Uchiha panicked as he dodged a seemingly endless wave of bolts. Although it irked him how he was being taken lightly, the lightshow above forced him to realize his limits. It was abundantly clear what her intention with this training was.
Capitalizing on his distraction, Mikoto focused three bolts in Sasuke's path at different points, forcing him to find the singular opening and dodge in that direction within a split second. Still, it was obvious from the new burns searing his skin that Sasuke had been a little too slow.
Clearly, her thought was, 'if I terrify you with overwhelming force, other shinobi will be tame in comparison.' Well, that and having to react to these bolts would do wonders for his combat speed and reaction time.
"Isn't this a little much mom!?" Sasuke yelled out, doing his best to communicate through the storm.
He dodged left, back, left again, and finally body-flickered forward. This time, he was just fast enough to dodge the consecutive stream of bolts.
"Oh? Is this too hard for you Sasuke? Is your resolve that weak?" This time, he was surrounded by lightning bolts, the thunder's roar nearly drowning out her condescension.
'Earth Release: Tunneling Jutsu.' He ran through the hand signs of a jutsu Mikoto had made him perfect in the last few days. Since the jutsu was so simple, it only needed two.
In a moment, he sank beneath the earth as if it were a pond. Again though, he wasn't fast enough.
Once the lightning hit, the resulting explosion blasted him out of the ground; he hadn't been able to sink deep enough to fully escape.
Stumbling to his feet as fast as he could in his tattered body, Sasuke didn't respond to his mother's taunt. Instead, his sharingan's fully matured form glared into her mirthful gaze. What pissed him off the most was her lack of an active sharingan; she hadn't bothered activating it.
This whole training had made something very clear to him; their eyes' copy function could only go so far. In their clan's recent history, he'd only known his brother to create some new techniques, but those were mostly minor variations of existing ones. In fact, that was a trend with their clan. They knew thousands of jutsu but created very little.
Seeing this endless storm reminded him of his own folly, of how deep the hole he trapped himself in really was. He may have been trying to create his new nature transformation, but he hadn't been too motivated in its creation. After all, even if he learned it, there would be very few jutsu to learn and Konoha had none of them. Seeing his mom's terrifying display though, he knew his vision was shortsighted. Without even considering her scorch release, she had taken something known to a new extreme; she redefined the limits of lightning release.
Sasuke gritted his teeth frustratedly. If only he had tried harder earlier.
'I need to get stronger. I can't keep limiting myself like this!' He furiously thought, determination once again filling his spirit.
This hell continued for hours before he was given the rest he craved.
(Naruto's Point of View)
Slumped against a tree trunk was the battered form of Naruto who breathed laboriously after an extensive training session. Next to him was an odd-looking man.
He stands at six feet tall and has short brown hair and black, almond-shaped eyes. He's wearing the standard Konoha Jonin uniform with a neck portion extending up to his chin. Another notable feature of his outfit is his happuri-style forehead protector that frames his face, like the Second Hokage had. If a man could look like a block of wood, this man would have fit the bill.
"*Pant* *Pant*… Sensei *Pant*, what's next?" Naruto asked, exhaustion breaking his sentence flow.
"Hmm… we've made adequate progress on your wood clones, basic wood manipulation, and now your activation speed for the wood bullet jutsu. We have one more exercise before we're done for today." The man explained, his tone reflecting his satisfaction at Naruto's progress.
They had been here for hours working on Naruto's newly discovered nature transformation. In addition to the training he's receiving from his parents, he was also assigned another supplementary sensei, ANBU member Tenzo. He was the only other shinobi in the village with access to the First Hokage's version of Wood Release, even if to a lesser degree.
Surrounding them was a menagerie of wooden constructs burrowing out of the surrounding forest above and the fertile soil below. Their training session had turned this section of the leaf training zone's outskirts into a 'war zone.' It was one of the few places in this training area that hadn't been polluted by the poisoned nature chakra and now it was a mess.
Naruto contemplated his sensei's words. Every instinct in his body demanded he complain, that he try to escape this grueling session. While he may have excess stamina, wood release demands that excess. For the first time in his life, he felt the pain of his classmates, the pain of stamina management. Still, he wouldn't give in; he wouldn't allow a repeat of their experience in the wave.
As such, he didn't respond; he only looked his sensei in the eyes with still burning, if tired, determination.
Giving the boy a curt nod, Tenzo continued, "For the next hour, I'm going to hunt you. You're going to make shadow clones and have them each do their best to hide in the surrounding area. I'm going to hunt each of them. You'll use ten shadow clones each time and we'll repeat the exercise until I'm satisfied. Each iteration, we'll review how each did after you collect the gathered memories from the clone's dispelling."
A groan escaped Naruto's lips as he braced himself for the inevitably annoying upcoming hour.
Still, he determinedly followed up with, "Yes Sensei!"
(Sakura's Point of View)
Stripped down and strapped to a table in one of the Konoha hospital's sealed off basement rooms, Sakura was half-regretting her decision to accept this lady's training. After impressing Uzume with her progress on the assigned textbook, the older Uzumaki decided to give her a chance. Although she couldn't finish the book in time, she wasn't meant to; it was a simple deception to draw out her best result.
Still, according to Uzume, her physical condition was abysmal and needed to be improved. To reach the minimum level for Sakura to be worth her time, it would simply take too long. As such, she decided to give Sakura a condition; she would take Sakura in as a probationary student if she managed to both go through a special set of medical procedures and impress her within a month of lessons.
Uzume was known for her scientific study of bloodlines. This is something that translates to her medical specialties in genetics, chakra-based illnesses, and bloodline transfusion. Although she could perform any known surgery performed in Konoha's hospitals like Tsunade could, she was known for her transcendent skill in bloodlines. In fact, the procedure she was performing on Sakura was her magnum opus; it let her awaken dormant bloodlines in shinobi.
Anyone who uses chakra has bloodline traits that exist as a combination of their chakra and their genes. Some excellent shinobi are lucky to awaken these traits during their careers; these will then have higher chances of manifesting in their children, leading to the creation of powerful family clans. Of course, that requires a powerful shinobi to kick off the process. Uzume's procedure forcefully stimulates these traits and awakens them regardless of the user's current strength.
It was a risk. They could only manifest one, but they had the strong chance of awakening multiple recessive bloodline traits. Therefore, these would often combine into and create a new bloodline. It's just that the new bloodline can express more than one trait. The Nara Clan is a good example; they have a high affinity for Yin Release, exceptional inborn intelligence, and a drawback of the propensity for sloth.
Of course, as all biological traits are, new traits could be either a boon or a devastating curse. This sometimes results in the awakening of a debilitating set of traits, ruining the prospects of a solid civilian-born shinobi. As such, this procedure was classified at the highest level, requiring both the Hokage's approval and the signing of multiple waivers before performing. Even still, there was a long wait list managed by the Hokage, making on-demand surgeries virtually impossible. The only reason Sakura received this opportunity was her placement on Team 7.
Still, aside from the risk, there was another problem.
Uzume hovered over the girl with hands glowing in a scarlet-red-colored chakra. Inscribed on the backs of her hands were rose-shaped seals glowing in a scarlet-red light. Out from those, sprouted vine-shaped markings that extended from the backs of her hands, around her forearms, and up to her elbow, glowing in the same-colored light.
With her preparations complete, her hands lowered until they touched Sakura's chest, right above her heart. The instant they made contact, an ungodly scream exploded from Sakura's mouth as she felt like her blood turned to molten lava. She could distinctly feel the bone marrow, blood vessels, and internal organs flood with foreign chakra. The scarlet chakra wormed its way into every nook and cranny of her body, though it only actively affected the specific regions Uzume was focusing on at any given time.
Unfortunately, the results she wanted wouldn't be quick or immediate. It was a slow process that required her to be strapped to this table and fully conscious for at least another week depending on how poor her physical condition was. It would be done through multiple long and grueling sessions for the young kunoichi. Being sedated or passing out would limit the results, so this was also part of her test. When she was done though… Regardless of her awakened bloodline traits, she'd at least be physically on par with the rest of her classmates, have a new bloodline to play with, all while having a healthy physique fit for a kunoichi.
Only when this was done would she be worthy of instruction.
Sakura’s bloodline won’t change her established canon traits. It’ll basically be used to explain her prodigious chakra control. Her control in the series makes no sense if ‘hard work’ is the justification. Regardless of the volume of chakra she controls [before and after the Strength of a Hundred Seal plus the lent Kurama chakra], her control never falters, even when she’s never handled that volume before. She’s also far more talented than Tsunade Senju whose physique and mindset at the same age eclipsed hers by miles; this also doesn’t make much sense. I don’t want to strip Sakura of those feats so I’m giving her a boost to justify all of that.