Naruto: Heaven Rewards Diligence

"Phew… I didn't expect such a gain!"

Naruto opened his eyes, surprise and delight flashing across his face.

This time, he had not only reviewed his Taijutsu—no, his Martial Arts System cultivation—but also repaired lingering flaws in his physical body. More importantly, he could now sense Natural Energy freely!

But recklessly absorbing Natural Energy into the human body was incredibly dangerous.

That was why Naruto's progress had always been cautious.

Otherwise, chaotic Natural Energy could easily run wild, and the end result might be turning into a statue of stone.

More than once, he had nearly petrified himself. The Immortal Chakra synthesized within his body would suddenly riot, and if it weren't for Naruto's immense willpower suppressing the rampage, the consequences would have been fatal.

Logically, Natural Energy—being the essence of heaven and earth—shouldn't cause petrification. Naruto could only conclude it was tied to the unique laws of this world.

Every world has its own rules and mysteries.

That must be why his body reacted that way.

Although the process had been excruciating, the results were rewarding. After long study, Naruto had finally grasped a method for Martial Arts cultivation. At the same time, he had thoroughly researched how to draw in Natural Energy and merge it into Immortal Chakra.

But what surprised him most was this—he had awakened an affinity for Natural Energy!

Now, he could absorb and recover Sage Chakra far more easily.

"Naruto! What exactly happened to you?"

A deep, shocked voice echoed.

"Kurama! I've already learned Sage Mode!"

Naruto grinned as he stepped into the sealed space. Inside, Kurama still loomed behind the bars of the great gate, though the environment mirrored the outside world now.

The Nine-Tails lowered its massive head, eyes narrowing as if demanding an explanation.

Kurama had always been aware of Naruto's training, but today's change was on another level.

"You know I'm not talking about just that."

Kurama's scarlet eyes blazed, fixing on him.

Naruto spread his hands helplessly. "Alright then… I'll show you."

He extended his hand, clenching it into a fist.

Kurama knew what this meant. Full connection—sharing memories directly.

Naturally, one could only share what they were willing to reveal. Naruto was now opening his mind to Kurama, showing everything he wished to share.

The fox's massive fist met Naruto's.

In an instant, Naruto's thoughts and insights poured into Kurama—his conception of the Martial Arts System, his research into Natural Energy, and the structure of Sage Mode itself.

When the transfer ended, Kurama's eyes widened. Shock filled the beast's vulpine face.

"Naruto! Should I call you a madman, a genius, or a monster?!"

His voice trembled with both awe and disbelief.

"The Martial Arts System… this could shake the entire shinobi world. I hate to admit it, but your achievement already rivals the Sage of Six Paths. Perhaps you really are the one the old man spoke of…"

Kurama muttered, half in amazement, half in resignation.

Deep in his heart, his recognition of Naruto grew stronger than ever. Compared to Hagoromo, Naruto's path seemed even more outrageous. After all—how old was Naruto?

And already, he had forged a system of Martial Arts to rival Ninjutsu.

The threshold for Martial Arts was low—anyone could train in it, though talent and resources determined progress. At its peak, it had clear limitations compared to the shinobi path. Yet this was still its infancy, Naruto's first creation. Its potential remained unmeasured.

At the same time, Naruto refined his Unbreakable Golden Body into a complete Martial Arts cultivation method—stronger than basic Taijutsu, incorporating the principles of the Six Styles and other powerful techniques.

"It's not as exaggerated as you think, Kurama. The road ahead is still long. Martial Arts may hold immense potential, but it lacks accumulated techniques and styles. Compared to the countless Ninjutsu, it's still in its growth stage."

Naruto's humility made Kurama blink.

In truth, he was right. In the early stages, the shinobi system far outpaced Martial Arts. Talented shinobi often reached Elite Jōnin in their teens, and some even reached Kage-level before twenty.

Uchiha Shisui, Itachi, and Minato Namikaze—all had proven that.

But shinobi burned bright and fast. Chakra, drawn from the life energy of body cells and the mind's spiritual energy, shortened their lifespans.

And since they entered the battlefield young, pushing themselves beyond their limits, many consumed their life force prematurely.

In war, who cared about a shortened life, as long as they survived the moment?

A shinobi's peak years were not long.

For most, their prime lay between thirty-five and forty-five, after which their condition inevitably began to decline.

More accurately, a ninja's true peak came at around forty.

By contrast, in the world of pirates (One Piece), a person's prime extended into their sixties. The gap between the two was staggering.

From the ages of six to twelve, a shinobi laid the foundation of their strength. The years from twelve to eighteen marked a period of explosive growth.

From eighteen to thirty, progress stabilized—most shinobi had already formed their core abilities, and future gains came slowly, though improvement was still possible. Beyond that point, only special methods could accelerate growth.

Kakashi, for instance, had wasted much of his golden period between twelve and eighteen. That was one reason he struggled to reach true Kage-level for so long, not just the burden of his Sharingan.

Zabuza's rise to quasi-Kage strength was thanks largely to Naruto's improved Chakra Refining Technique, which multiplied his chakra reserves and enhanced his Taijutsu.

If he wanted to climb higher, his only options were to further expand his chakra capacity, strengthen his physical body, or master powerful techniques such as S-rank jutsu.

But most S-rank jutsu were closely guarded secrets, making the leap to Kage-level all the more difficult.

From thirty to forty, most shinobi entered a stage of consolidation. Lifespans were short, and few reached the age of the Third Hokage. By then, further growth was nearly impossible—prolonged battles drained life force, leaving shinobi in their thirties and forties with the vitality of men twice their age in other worlds.

From forty-five to sixty, decline set in. The body began to wither, and peak strength became impossible to maintain.

Beyond sixty was the stage of decay. During the Konoha Crush, the Third Hokage was already at this point—his power fell rapidly with age.

This was the fatal drawback of the shinobi system.

In his youth, Hiruzen Sarutobi had been a prodigy without peer. Proficient in all five elemental releases, he earned the title of Professor of Ninjutsu. With his mastery, even several A-rank jutsu combined could rival S-rank techniques. His Great Dragon Fire Technique alone reached that level.

At his peak, he stood among the strongest of the Kage. Defeating even Orochimaru would not have been a problem.

But in his old age, his body could no longer keep up, and against his former student he was powerless.

That he had reached such heights without relying on any kekkei genkai was proof enough—Hiruzen Sarutobi was a true super-genius.

...

TN:

⚒️ Pa-treon-com/LordMerlin