Initial Fusion

With a plan in mind, Sasuke went to his parents' room, lifted the floorboards, and slowly climbed down.

This was a place Sasuke had seen his father, Uchiha Fugaku, enter one night. Sasuke didn't know exactly where it led, but he guessed it was likely his father's secret base.

I hope it's not where he hides his private stash of money!

After flipping the switch to return the floorboards to their original state, Sasuke muttered to himself and slowly descended the stairs. Since there were flames along the staircase providing light, Sasuke didn't have to worry about his vision.

Following the stairs down, Sasuke eventually arrived in a vast room containing a desk and a flag emblazoned with the Uchiha clan crest.

On the desk sat five scrolls, standing out in stark contrast to the dust covering the surface; they looked like they had been placed there quite recently.

"Itachi?"

Upon discovering the suspicious scrolls, the image of that "good brother" surfaced in Sasuke's mind. He immediately shook his head; now was not the time to think about such things. After all, the Ninja Academy would be starting in a month, and he needed to hurry up and master all the ninjutsu and taijutsu that the original Sasuke had known!

Host: Sasuke
Bloodline: Uchiha
Nature Transformation: Fire, Lightning
Kekkei Genkai: Sharingan
Chakra Level: Genin

Opening his system panel, this was the introduction Sasuke saw. Of course, this was just the most basic panel.

Ignoring the descriptive panel, Sasuke's gaze flickered slightly, and the information on the light screen before him gradually changed!

Basic Skills: [Transformation Technique: E-rank; 40/50] [Clone Technique: E-rank; 40/50] [Substitution Technique: E-rank; 40/50] [Body Flicker Technique: E-rank; 40/50] [Kunai Throwing: 400/1000] [Hand Seal Speed: 150/2000] [Shape Transformation: 200/2000] [Control Level: 100/2000]

Beyond the basic skills, the sub-panels included taijutsu, genjutsu, nature transformation, and Sharingan. Based on Sasuke's understanding, if he learned more in the future, there would likely be even more panels, but these weren't what Sasuke cared about right now.

What Sasuke cared about most right now was whether his identity would be exposed. After all, the original Sasuke was the top student in his class!

He had to keep in mind that the Ninja Academy held tests when the semester started! If he performed poorly, he could blame it on being in a bad mood, but Sasuke didn't want that. After all, being cool was a lifelong commitment!

The numbers displayed after the skills represented proficiency. Once proficiency reached its maximum, the skill could be fused with another skill—provided, of course, that both skills had reached perfection!

The proficiency cap for E-rank ninjutsu was 50, D-rank 100, C-rank 200, B-rank 500, A-rank 800, and S-rank 1000.

As for the skills with a proficiency cap of 2000, those were general ninja skills. Sasuke felt that once the proficiency of these skills reached their peak, there would be unique rewards. For example, if Hand Seal Speed reached perfection, Sasuke felt he might be able to perform one-handed seals, and if one-handed seals reached perfection, he reckoned he could just clap his hands together and summon whatever he wanted!

He didn't look at the remaining panels, not even the Sharingan panel. After all, he needed to slowly make everything from the original body his own.

First, Sasuke began training his hand seals, as every ninjutsu required them.

Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Ram, Monkey, Rooster, Dog, Boar—after honestly familiarizing himself with these seals, Sasuke's hand seal speed began to slowly increase. After a few rounds of training, Sasuke was already able to perform two seals per second!

[Hand Seal Speed: 200/2000]

After successfully mastering the basic seals, Sasuke looked at the hand seal speed displayed on the panel and felt a bit stunned. 200 represented two seals per second, so wouldn't the maximum be 20 seals per second?

"In the future, I might be able to crush enemies with pure hand speed!"

Looking at this change, Sasuke felt a secret thrill, then turned his gaze toward the Three Basic Techniques—Clone, Transformation, and Substitution—as these were essential skills for any ninja!

Closing the panel, Sasuke began to form seals according to the memories in his mind. With a "poof," another Sasuke appeared beside him!

[Clone Technique proficiency reached perfection!]

The moment this clone appeared, a notification screen appeared before Sasuke!

"Keep going!"

With a thought, Sasuke closed the notification panel, dismissed the clone, and began practicing the Substitution and Transformation techniques!

[Substitution Technique and Transformation Technique proficiency reached perfection!]

Looking at the light screen, Sasuke smiled slightly, then opened the panel to test the system's fusion function.

Fusion: [Special Fusion Opportunity: 1] [Ninjutsu Fusion: Ninjutsu that have reached perfection can be fused; no limit on the number of fusions!] [Nature Transformation Fusion: Kekkei Genkai] [Bloodline Fusion: Improve physique] [Cell Fusion: Transplant cells]

[Mangekyō Fusion: Advance to Eternal]

Looking at the description appearing on the fusion panel, Sasuke felt a surge of excitement, especially regarding the final Mangekyō Fusion. Although he didn't possess a Mangekyō at the moment, he reckoned he would be able to obtain a true, genuine Mangekyō in the future!

After all, weren't Mangekyō supposed to have all sorts of patterns? Even though it would be quite difficult to get his hands on any Mangekyō other than those belonging to his brother Itachi, and despite the fact that all fusions besides Ninjutsu Fusion required special fusion opportunities, that didn't stop Sasuke from daydreaming!

"Thinking too far ahead. Better check out the Ninjutsu Fusion first and see what's what!"

Lost in his fantasies, Sasuke shook his head to cast aside the urge to let out a wild laugh, turning his gaze toward the three options floating within the Ninjutsu Fusion menu.

Clone Technique, Transformation Technique, and Substitution Technique. Since there was no upper limit to Ninjutsu Fusion, Sasuke selected all three basic techniques and initiated the fusion process.

[Three Basic Techniques: 150/800; allows the user to use clones as substitution material, while simultaneously transforming the main body for disguise!]

Seeing the proficiency cap after the fusion, Sasuke felt a sense of disbelief—this was the cap for an A-rank ninjutsu!

However, since the clones created by the Clone Technique were merely illusions, this synthesized ninjutsu could only fool genin and some brainless chūnin; if he were to encounter a jōnin, Sasuke estimated it wouldn't be of much use!

Unless he could fuse it with a ninjutsu that even enemies couldn't distinguish from the real thing: Shadow Clone Technique!

"Take it slow! I haven't even graduated yet, so I can still steadily improve my strength!"

After testing the newly acquired Three Basic Techniques for a bit, Sasuke turned his gaze toward the five scrolls that were suspected to have been left behind by Itachi.

Transformation, Substitution, and Clone—the first fusion brought a pleasant surprise!

Asking all the big shots for votes (づ●─●)づ