'Sword Leap Flame!'
More accurately, it should be 'Sword Leap Flame - Modified!'
Uchiha Shisui's three sword techniques, arranged from easiest to most difficult, were Sword Leap Flame, Raging Wind Blade, and Sun Halo Dance.
Sword Leap Flame, a Fire Release-based Ninja Blade Technique, uses a katana to form a blazing blade that strikes enemies. It incorporates a partial Wind Attribute element.
Raging Wind Blade builds upon Sword Leap Flame by incorporating the Lightning Flash Technique.
As the user charges forward, they continuously build momentum, unleashing a massive flaming blade with greater speed and destructive power.
Sun Halo Dance is essentially an amplified version of Raging Wind Blade.
When executed in conjunction with the Lightning Flash Technique, it unleashes three massive blades of flaming light in rapid succession.
Since Sasuke hadn't yet mastered Shisui's Lightning Flash Technique, he had no choice but to start with Sword Leap Flame, the most fundamental of the three.
However, a significant obstacle lay before him: he lacked Wind Attribute Chakra.
This was a particularly awkward predicament for Sasuke.
Sword Leap Flame was indeed primarily a Ninja Blade Technique rooted in Uchiha-style Swordsmanship and Fire Release Ninjutsu.
However, following the principle of "wind fueling fire," Shisui had incorporated elements of Wind Attribute Chakra to enhance both the technique's power and speed.
As everyone knew, Wind and Lightning were two attributes renowned for their speed—the former for its agility, the latter for its swiftness.
Sasuke currently lacked Wind Attribute Chakra.
Developing a new Chakra Attribute typically required a Jonin-level ninja one to two years of meticulous study.
Sasuke couldn't achieve this yet, nor did he have the time to dedicate his focus to it.
As for incorporating Lightning Attribute Chakra, Sasuke hadn't even learned the basic Lightning Release Ninjutsu yet.
How could he possibly integrate the properties of Lightning Release Chakra?
However, this challenge didn't deter Sasuke.
Since he lacked Wind Attribute Chakra, he forged his own path: specializing in enhancing Sword Leap Flame's Fire Attribute Chakra and incorporating elements of Iaijutsu!
'If the conditions don't exist, we'll create them ourselves!'
'Originally, there was no road; it is only through many people walking that a path is made!'
The education and values he had cultivated in his previous life had instilled in him a spirit of exploration, a fearlessness in the face of adversity, and a willingness to navigate even the most circuitous paths.
While Fire Release Chakra wasn't renowned for its speed, its instantaneous burst power surpassed both Wind and Lightning Releases.
And burst power often determines an object's instantaneous velocity!
The faster the molecular motion, the higher the temperature and the hotter the object; conversely, the slower the molecular motion, the lower the temperature and the colder the object.
By channeling Fire Release Chakra into the blade while simultaneously coating it with microscopic chakra particles that mimic molecular motion—rapidly rubbing against each other in constant motion—Sasuke aimed to amplify the blade's explosive power and temperature.
Since he wasn't using his own body, he didn't need to worry about injury, allowing him to execute this process at a relatively faster pace.
This was the first step in modifying his Sword Leap Flame technique. The second step involved integrating elements of Iaijutsu.
Sword Leap Flame wasn't Iaijutsu; it was an exceedingly simple straight slash.
Iaijutsu, on the other hand, is a sword technique that emphasizes drawing the blade in an instant, leaving no opening for the enemy, and achieving victory through a single, decisive strike.
Though a common technique—essentially just a quick draw and slash—mastering it requires years of dedicated practice.
The katana and its sheath both possess a subtle curve. Iaijutsu leverages this curvature and the friction generated during the draw to create an explosive burst of power.
By drawing the blade along its natural arc and executing the slash in a single motion, it achieves a lethal, one-strike kill.
Having mastered these two steps, Sasuke believed that his Sword Leap Flame - Modified, when used against an opponent of equal skill, was now on par with Shisui's original technique, even surpassing it in terms of raw power.
"In a way, I've truly modified this technique," Sasuke murmured to himself as he sheathed the katana, his gaze fixed on the distant miniature mountain.
A rare hint of genuine joy and satisfaction flickered in his voice.
"Still, this is merely a refinement of someone else's foundation. I can't afford to grow complacent. But someday, I'll create a signature technique of my own!"
After quietly cautioning himself, Sasuke sensed a gaze fixed upon him. His heart quickened as he followed the line of sight.
On the rooftop, a cat had materialized seemingly from nowhere—it was Denka.
And strapped to Denka's back were five small scrolls!
'The things I need have arrived!'
A faint smile touched Sasuke's lips as he strode toward Denka.
After his usual nightly routine of reviewing the day's lessons, meditation, and cultivation, Sasuke retrieved the ninjutsu scroll he had obtained from Denka earlier that day.
The first scroll he unrolled was the Lightning Release Ninjutsu Scroll!
Most of its contents consisted of basic theoretical knowledge about Lightning Release Ninjutsu, along with D-rank and C-rank techniques such as Lightning Release: Earth Run and Lightning Release: Lightning Ball.
There wasn't a single B-rank or higher-level ninjutsu listed.
Yet Sasuke wasn't disappointed, nor did he underestimate the scroll's value simply because it contained only the basics.
On the contrary, he studied it with meticulous attention, scrutinizing every detail.
An hour later, Sasuke set down the Lightning Release Ninjutsu Scroll and exhaled deeply.
"As expected, there's no mention of how to stimulate and activate bodily cells using Lightning Release Chakra."
Lightning Release, in addition to its offensive power, high penetration, and ability to paralyze enemies, possessed another unique characteristic: the ability to enhance the user's speed by activating bodily cells through chakra.
In the original series, only two techniques exhibited this property: Kakashi's Raikiri and the Raikage clan's Lightning Release Chakra Mode.
Kakashi's Raikiri stimulates the muscles in the caster's legs and arms, enhancing the speed of his straight-line thrusts and granting his arms tremendous piercing power.
The Raikage lineage's Lightning Release Chakra Mode takes this a step further, enhancing the entire body, including the brain's reaction speed.
Without the aid of the Sharingan, Kakashi's original Raikiri lacked any reaction speed enhancement.
When he first created it, the thrust's speed was so extreme that not only could enemies not react, but even Kakashi himself couldn't keep up.
Against even slightly stronger opponents, this flaw would be instantly exploited, leaving him vulnerable to counterattacks.
The Lightning Release Chakra Mode concentrates Lightning Release Chakra throughout the entire body, enveloping the user in chakra and lightning.
This process activates the physical body, enabling the Lightning Flash Technique, significantly enhancing defense, and stimulating nerve conductivity through internal electrical surges.
It can even manifest as a lightning-infused Lightning Release Armor, protecting the caster's body.
'It seems I'll have to keep an eye on Kakashi in the future.'
It was impossible to deny the disappointment at the lack of a Lightning Release Chakra method for activating physical cells mentioned above.
Sasuke had already mentally prepared himself for this. After all, Lightning Release Chakra itself was an extremely dangerous type of chakra.
A single misstep could result in killing himself rather than his enemy.
Moreover, using Lightning Release Chakra to activate physical cells was a rare and advanced technique within Lightning Release.
It was unlikely that methods for cultivating such a skill would be found in basic or low-level Lightning Release Ninjutsu.
Although he lacked a method for stimulating physical cells with elemental chakra, Sasuke still resolved to diligently practice these lower-tier Lightning Release Ninjutsu in the future.
After all, even the tallest skyscraper starts from the ground. Building a solid foundation was more important than anything else!
In the original story, before the final round of the Chunin Exams, Sasuke had spent a month, pushing himself to his limits, just to master the Chidori.
Kakashi's exact words to Guy at the time were:
"Sasuke nearly lost his life mastering this technique!"
This clearly demonstrated that the Chidori was no easy feat to master.
However, at that time, Sasuke hadn't grasped any fundamental Lightning Release Ninjutsu.
At least, neither the manga nor the anime showed any indication that he knew any Lightning Release Ninjutsu before learning the Chidori.
If he began training in Lightning Release Ninjutsu now, establishing a solid foundation, he reasoned that when he eventually learned the Chidori, it would take him far less time than it had taken his original self.