Book of Ninja: An item used to increase ninjutsu levels. Acquisition method: awarded whenever the host levels up.
As the system's explanation appeared in his mind, Luo Yu froze. "Awarded for leveling up?"
"Isn't that just a skill point?"
With a skill point in hand, naturally, upgrading his Mangekyo took priority.
After all, the Kamui Mangekyo could harness space-time power to teleport freely into any space, and it even came with a separate dimension that only the Kamui Mangekyo could open.
It offered a tremendous sense of security.
Unfortunately, his Kamui Mangekyo's current level was too low for him to wield it.
With that in mind, Luo Yu opened the Kamui Mangekyo panel and clicked the upgrade button.
Insufficient materials. Unable to upgrade!
At that, Luo Yu took a closer look.
[Mangekyo upgrade requirements: Divine Pupil Stone 0/1]
So the material needed to upgrade the Kamui Mangekyo wasn't the Book of Ninja, but Divine Pupil Stone.
Luo Yu had heard his homeroom teacher explain that Divine Pupil Stone was a rare material that enhanced ocular technique training. Even a tiny piece sold for one million ninja coins at the Ninja Association.
The Byakugan clan in the Land of the Dragon's imperial capital had even lavishly built a training facility out of Divine Pupil Stone, exclusively for the clan's geniuses.
Of course, such an expensive material was beyond anything Luo Yu could hope for right now.
"Looks like upgrading Kamui will have to wait."
Luo Yu shook his head helplessly.
Even with a system, spending money was always the most reliable strategy.
Having accepted the situation, Luo Yu asked the system, "What level do I need to upgrade the Kamui Mangekyo to before I get more abilities?"
The system promptly answered, "Once the Mangekyo talent is upgraded to level three and the next-stage template is unlocked, the Mangekyo will unlock new abilities."
Obito Uchiha [Night of the Uchiha Massacre]!
Luo Yu was stunned. "So the template can be upgraded too? Why didn't you tell me about something this good sooner?"
After all, if massacre-era Obito was available, then Nine-Tails' Rampage Obito, Goofy Obito Uzumaki, White Mask Obito, and Six Paths Obito were bound to be available too.
Once he unlocked the Six Paths Obito template, he would surely stand at the pinnacle of the world.
At that thought, Luo Yu eagerly asked, "What are the requirements for unlocking massacre-era Obito?"
The host must reach Jonin rank.
Jonin?
In other words, once both his chakra and stamina reached 2,500, he could unlock the massacre-era Obito template.
Even with the system's help, he couldn't hope to achieve that without a few months of effort.
He should focus on how to use the Book of Ninja first.
With that in mind, Luo Yu turned his attention to the upgrade requirements for his other talents and ninjutsu.
[Hashirama Cells upgrade requirements: Yamato legacy fragment 0/1] [Great Fireball upgrade requirements: Book of Ninja 0/1 or Nameless Legacy Fragments proficient in Fire Release 0/5] [Phoenix Flower Fire upgrade requirements: Book of Ninja 0/1 or Nameless Legacy Fragments proficient in Fire Release 0/5] [Advent of a World of Flowering Trees upgrade requirements: White Zetsu legacy fragment 0/1] [Hell's Turmoil upgrade requirements: White Zetsu legacy 0/1]
Realization dawned on Luo Yu. "Could it be that the Book of Ninja can only upgrade ninjutsu of the basic elemental natures?"
"While Kekkei Genkai ninjutsu like Wood Release require legacy fragments of the corresponding nature?"
That is correct.
With the system confirming his theory, Luo Yu rubbed his chin in thought.
Most ninja legacy fragments in this world came from the Otherworld Secret Realm.
It was essentially a sanctuary for strange beasts, making it especially dangerous for humans.
Even the lowest-level secret realms required Genin certification to explore.
Although fragments weren't as valuable as complete legacies, they were still worth the risk to ninjas.
By fusing with the corresponding fragments, someone could inherit a portion of that ninja's abilities.
For example, absorbing a Yamato legacy fragment offered a high chance of awakening earth, water, yang, and wood natures.
With luck, it could even allow the user to grasp the ninjutsu Yamato had used.
Of course, the most valuable outcome was awakening the user's wood nature.
In ancient times, the mighty figure who had absorbed Hashirama Senju's legacy had gone on to make his name through his formidable Wood Release. The world had reverently called him "Emperor Shinra."
The Land of the Dragon was the nation Emperor Shinra had founded in the wastelands using Wood Release, after driving out vast numbers of the strange beasts occupying Blue Star.
That was why everyone on Blue Star, young and old alike, knew how powerful Wood Release was.
Legacy quality was divided into gray, white, green, blue, purple, and orange.
Nameless Inheritance that could enhance basic elemental ninjutsu was of the lowest quality: gray.
For other people, using one would merely increase their chakra reserves, with only a very small chance of letting them grasp a ninjutsu of the corresponding nature.
Even then, those were only one-star ninjutsu. Only with luck could they grasp a one-and-a-half-star ninjutsu.
Despite that, Nameless Inheritance was still a luxury beyond the reach of Common families.
White Zetsu legacies, meanwhile, were white quality, while Yamato legacies were green quality.
Green legacy fragments only appeared in Jonin-level secret realms, and twenty Green Quality fragments were needed to form a complete legacy.
So even a Jonin would still need a great deal of time to obtain a complete green legacy.
Otherwise, they could only buy one for a hefty sum.
Fortunately, upgrading Hashirama Cells only required fragments.
Setting aside the ninjutsu he couldn't upgrade this early on, Luo Yu decisively used the Book of Ninja on Fire Release: Great Fireball.
[Fire Release: Great Fireball Technique level +1!]
As the system notification appeared in his vision, Luo Yu immediately felt a flood of insights about the Great Fireball pour into his mind.
In just half a minute, he gained a deeper understanding of the otherwise unremarkable Great Fireball.
"Fire Release: Great Fireball Technique!"
Luo Yu tried casting a Great Fireball toward an open patch of ground.
This time, he formed his hand seals twice as fast.
He also effortlessly limited its consumption to 3 chakra.
Even so, the Great Fireball was somewhat more powerful than the one that had previously cost 5 chakra.
All these signs showed that his proficiency with the Great Fireball had already reached minor mastery.
"Could every level increase in a ninjutsu raise its proficiency by one stage?"
Luo Yu was inwardly shaken.
The Ninja Association divided ninjutsu proficiency into six stages.
Beginner, minor mastery, proficiency, major mastery, pinnacle, and return to simplicity.
Once proficiency increased, both control and ninjutsu power would undergo a qualitative transformation.
In the hands of an expert, a low-star ninjutsu with high proficiency could easily rival a high-star ninjutsu with low proficiency!
But...
Aside from certain genius ninjas, most Common people needed repeated practice to improve their ninjutsu proficiency, carefully developing their understanding as they used it.
The process was maddeningly elusive.
As a result, most Common ninjas pursued high-star ninjutsu and largely left proficiency to chance.
"Every time I advance a tier, I get another ninjutsu level."
"Doesn't that mean I can train the Great Fireball to return to simplicity by the time I reach third-tier Genin?"
"This system is ridiculously overpowered!"
Luo Yu could scarcely believe it. After all, even many Super Kage experts might not manage to train the Great Fireball to return to simplicity.
If he truly mastered the Great Fireball at maximum proficiency while still a Genin, his talent would surely shock the entire world.
With that thought, Luo Yu clicked open the Great Fireball's details.
[Fire Release: Great Fireball Technique upgrade requirements: Book of Ninja 0/2 or Nameless Inheritance proficient in Fire Release 0/10]
The upgrade requirements had increased!
Ten Nameless Legacy Fragments could be combined into one complete Nameless Inheritance.
Sure enough, it wouldn't be that easy.
Improving his basic attributes first would be more practical.
With a helpless sigh, Luo Yu finished collecting Stonefang, activated his Three-Tomoe Sharingan again, and searched for nearby prey.
The commotion Luo Yu had caused while roasting the rabbits earlier had sent all the nearby strange beasts scattering.
Moreover, the strange beasts living in the surrounding area now knew how dangerous Luo Yu was, so they would certainly be especially wary for a while.
Wiping out another whole group with a single Great Fireball, as he had earlier, would be almost impossible.
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