No one knew how long passed. Katsuyu slowly began to speak, supplementing the history it knew.
About the past interactions between the Sage of Six Paths, his brother, and the Toad Sage, and the specific details of that mythical battle that sealed Kaguya.
Their information mutually corroborated, piecing together a more complete picture of historical truth.
Then, Menma steered the conversation towards the 'gods' that existed in legends and forbidden techniques, such as the ShiniGami, the Jashin, and so on.
Menma raised his head and asked, "Regarding these beings called 'gods', how much does Katsuyu-sama know?"
Katsuyu Sage pondered for a moment, its gentle female voice carrying reminiscence: "Over a thousand years ago, many beings revered as 'gods' did indeed exist on this land. Some were natural spirits born from the highly condensed Natural Energy that gained consciousness. Others were incarnations of faith coalesced from the strong collective beliefs and wishes of humans. But in the final analysis, the existence of most of them depended on abundant Natural Energy."
"A thousand years ago, when Otsutsuki Kaguya planted the God Tree, it was an enormous plunder of Natural Energy. Many weaker gods dissipated as a result."
"Faith is a special kind of power," Katsuyu explained. "It doesn't depend entirely on Natural Energy, but originates from human emotions and will. So even if Natural Energy is exhausted, as long as there are still believers, these gods will not completely disappear."
"Beings like the ShiniGami, the Jashin… they are already the best of them, able to sustain their existence by relying on specific rituals and human faith as 'offerings'."
This cross-millennium conversation lasted for several hours.
Menma obtained a large amount of precious historical fragments. Although Katsuyu Sage, having long resided in the sacred land, knew little about specific worldly events, its perspective and knowledge about Natural Energy provided Menma with crucially important corroboration and inspiration.
Finally, Menma looked at Katsuyu Sage's vast body, almost merged with the entire Shikkotsu Forest's space, and asked a question he had pondered for a long time: "Katsuyu-sama, for over a thousand years, you have continuously signed contracts with humans, seeking contractors... is it because you want to leave this relatively enclosed 'home'?"
In Menma's view, the Three Great Sage Regions were certainly sanctuaries, but being trapped here year after year, isolated from the vast Ninja World, was it not also a kind of beautiful cage?
Katsuyu Sage's voice carried a faint tinge of loneliness: "Perhaps... that is partly the reason."
"My main body is too vast. If I were to appear fully in the Ninja World, it would cause enormous panic and unnecessary trouble. There are always humans yearning for power who would come seeking me out, either begging or threatening... it's very troublesome."
For it, with its immeasurable lifespan, human lives were as brief as a flash of flower, but the frequent disturbances still tired it.
Menma thoughtfully nodded. He pinched his chin and proposed a suggestion: "In the southern part of the Ninja Continent, near the warm sea areas and the equator, I plan to designate a vast primeval forest nature reserve in the future, prohibiting ordinary people from entering. If Katsuyu-sama is interested, perhaps you could open up a new habitat there, where you could occasionally go to relax."
He recalled the vast rainforest of the Land of Rivers from his memories. Once the Fourth Great Ninja War began, the first thing to be swallowed would be the Land of Rivers. At that time, the dense primeval rainforest of the Land of Rivers could be developed into a protected area.
Katsuyu Sage, however, slowly shook its head, its voice gentle but with realistic considerations: "I am very grateful for your kindness, Menma-chan."
"But my main body is truly too vast. Even after signing the contract with Tsunade-chan, the most she can do with all her might and summon at once is less than one-tenth of my main body. For me to completely leave Shikkotsu Forest and move freely in the Ninja World... is impossible."
"Not even one-tenth can be fully summoned?" Menma repeated softly.
Then, the corner of his mouth slowly curled into a smile.
"I see... Well then, I am truly interested."
Before his words faded, an indescribable mighty and vast Chakra suddenly erupted from within Menma!
A dazzling golden Chakra sprayed out from his body, instantly forming a magnificent and majestic golden Chakra cloak!
In the center of his forehead, a Tenseigan as pure as gold, yet containing the vast power of the stars, slowly opened!
The golden light even dispersed the thick fog around him, illuminating the entire swamp.
In that light, Menma's figure was like a god descending to the mortal realm.
What shocked Katsuyu Sage even more was that, on either side of his forehead, a pair of small yet solid dragon horns, as if formed from pure energy, pierced his skin and slowly grew out!
At this moment, Menma hovered in mid-air, radiating a divine pressure and light, a completely different person from his usual low-key appearance!
The eyes at the ends of Katsuyu's antennae suddenly contracted. Feeling this power similar to the Otsutsuki Clan, its spirit was shaken like never before!
This human youth... made it seem to see Kaguya after she had eaten the God Tree's fruit!
Katsuyu Sage's massive body trembled slightly in the pervasive moisture, not from fear, but from a shock that spanned a thousand years.
The Chakra Tenseigan Mode that Menma was displaying awakened memories buried within it for a millennium.
It was from the distant past, when the God Tree stood tall over the land, when that woman named Otsutsuki Kaguya ruled over this planet with a similar presence, radiating that same oppressive force.
However, Menma's Chakra aura was not entirely the same as Kaguya's.
Kaguya's power was closer to pure 'devouring', like a black hole.
Whereas the golden Chakra flowing around this young man, while equally vast and mighty, carried a kind of 'inclusive' vitality, as if the stars themselves were breathing and evolving.
This subtle difference allowed Katsuyu Sage, beyond its shock, to see a glimmer of a completely different possibility.
Freedom...
This word carried complex and heavy meaning for Katsuyu Sage, who possessed nearly eternal life.
Although it could use contractors like Tsunade to summon a small part of itself to the Ninja World, briefly feeling the warmth of the sun, the caress of the breeze, and observing the changes in the human world…
That was nothing more than peeking at a small corner of the world through the cracks of a cage.
Its true body, as vast as a mountain range, had been confined for a thousand years to this Shikkotsu Forest… a place safe, yet ultimately oppressive.
Every 'breath of fresh air' felt more like a pitiful consolation for a long-term imprisonment.
Now, this young man before it had not only demonstrated power comparable to Kaguya but also seemed... to be genuinely considering the possibility of taking it out of this 'cage'.
This promise was like a stone thrown into an ancient well, stirring unprecedented ripples in Katsuyu Sage's heart, which had been calm for too long.
The longing for a wider world, the yearning for true freedom, like seeds long dormant, began to quietly sprout.
But a thousand years of existence had endowed it with patience and caution far surpassing that of humans.
Behind the promises of humans, especially powerful and ambitious ones, often lay complex calculations and demands.
Katsuyu Sage's gentle tentacles observed Menma, floating in mid-air like a golden deity. Its gentle female voice sounded again: "What astonishing power... It reminds me of that [Princess of the Moon]."
"So then, Menma, if you truly intend to help me leave this place, what must I pay in return? For all things in the world, exchange brings balance. I do not think you would extend such a great helping hand to an alien being's 'freedom' for no reason."
It had lived too long, seeing too many contracts that began with 'help' but eventually devolved into one-sided demands or even enslavement.
The dazzling golden light around Menma slowly faded. The Tenseigan on his forehead and the dragon horns gradually disappeared. He lightly landed back on the curved, pale white tree trunk, his posture returning to its previous state.
Facing Katsuyu Sage's direct question, he did not evade but answered frankly: "You are right, I do have a request. I wish to learn Sage Arts from you."
"The true method of perceiving, absorbing, and utilizing Natural Energy."
This answer made Katsuyu Sage pause slightly. It was clearly quite surprised, its massive body lowering a bit, drawing closer as if to examine Menma more carefully. "Learn... Sage Arts?"
Its tone was full of puzzlement.
"I can sense that the Chakra within you is already no less than, perhaps even... surpassing Kaguya from a thousand years ago."
"And within you, besides the power of the stars, there are forces even I cannot clearly see. Why turn back to seek the more primitive Natural Energy? The power of Sage Arts, for you..."
Katsuyu Sage's question was not without reason.
In its view, possessing the [Power of the Tenseigan], Menma was already on the level of the Sage of Six Paths or Otsutsuki Kaguya.
Menma sat cross-legged on the tree trunk, his hands folded in his lap, his expression serious. "That is precisely one of the key points I wish to clarify. Katsuyu-sama, in your opinion, what is the essential difference between Senjutsu Chakra and the Chakra I use, or rather, the Chakra used by ordinary Ninja as passed down through the Ninshu tradition established by the Sage of Six Paths?"
He did not underestimate Sage Arts. On the contrary, precisely because he valued it, he had to understand its essence.
In the original work, Sage Arts could effectively damage even the Ten-Tails' Jinchuriki and Kaguya, which in itself speaks to its uniqueness.
Katsuyu Sage was silent for a moment, as if organizing its words.
"The difference..." Its gentle, wise voice slowly echoed through the mist permeating Shikkotsu Forest. "Hmm, there is one, but perhaps it's not the kind of 'hierarchy' you humans usually understand. Let me think about how to describe it..."
"Natural Energy exists in every inch of soil, every wisp of air, every drop of water on this planet, even within the cycle of life and death. It is like the omnipresent 'soil' and 'nutrients'… the foundation upon which all life, including us summoning beasts, including you humans, is born, grows, and exists."
"Any living being, as long as it lives, is instinctively absorbing extremely minute amounts of Natural Energy to maintain the most basic cycle of its own life. It's just that most individuals cannot clearly 'perceive' this process, let alone 'control' it."
Katsuyu Sage paused slightly, as if observing Menma's level of understanding, then continued:
"And when an individual, usually a human with exceptional talent or one who has undergone special training, begins to clearly 'sense' this omnipresent energy, and actively, consciously guides, absorbs, and fuses it with their internal [Physical Energy] and [Spiritual Energy] according to a certain balanced ratio..."
"The new energy produced at this point is [Senjutsu Chakra]."
"It is not water without a source, but rather a bridge connecting individual life to the primordial power of the planet that nurtured it."
"As for the [Chakra] you commonly use now..." Katsuyu Sage's voice carried a hint of reminiscence and complexity.
"That is more like... a 'technology' brought by the Otsutsuki Clan. They treated Natural Energy as a 'resource', refining, transforming, and perhaps even 'domesticating' it in ways we do not yet fully understand, making it a 'form of energy' more easily utilized by their own bloodline inheritance and use, and also more easily mass-extracted and aggregated through tools like the [God Tree]."
"It has not completely severed its root from Natural Energy, but it has been transformed, becoming more dependent on specific bloodlines and technique systems."
This explanation, like parting the fog, gave Menma a clearer framework for understanding Natural Energy, Chakra, and Sage Arts.
Natural Energy is the source. Senjutsu Chakra is the 'active energy' that actively connects and fuses the source with the self. Conventional Chakra is the 'standardized product' of Natural Energy processed by the Otsutsuki Clan. Though powerful and systematically mature, it may have lost certain primordial qualities and is deeply bound to the God Tree System.
"Then, what about the power within me?" Menma raised his own hand, examining it carefully, while again subtly mobilizing a trace of Dark Kyuubi's Chakra, letting a faint dark red Chakra flow through his palm.
"According to your perception, what is the connection between my current state and Natural Energy?"
Katsuyu Sage's pair of huge tentacles moved forward, as if intently 'looking' at the wisp of dark red Chakra in Menma's palm.
After a good while, it emitted a murmur tinged with obvious confusion: "Strange... very strange..."
"This dark red Chakra you are mobilizing contains creation, destruction... and a sense of nothingness. It is different from any Chakra I know. It's closer to... hmm, I don't know how to describe it..."
Menma then withdrew this Dark Kyuubi Chakra as well.
Katsuyu Sage's antennae swayed slightly: "Eh?"
"When you withdrew this power, the Natural Energy aura lingering around your body... became exceptionally thin. It is even... not significantly different from ordinary humans in the Ninja World who have never undergone any training. This is not logical..."
"Logically speaking, for an individual with your powerful vitality and spiritual power, even without actively practicing Sage Arts, the unconsciously emitted life field would naturally attract and fuse more Natural Energy."
A glint of understanding flashed in Menma's eyes.
This might be a potential influence brought to him by the [Limited Tsukuyomi World].
In that virtual world, perhaps the settings for Natural Energy were already vague, or even non-existent, or perhaps it existed in another unrecognized form.
This caused the affinity and perceptual baseline for Natural Energy deep within his soul to differ from those of native residents of the Ninja World.
He was like someone accustomed to breathing a certain type of synthetic air suddenly arriving in a natural environment with a different oxygen concentration. While physiologically he could adapt, that most subtle perception and instinctive resonance needed to be re-established.
"I understand." Menma lowered his hand, most of his doubts resolved.
"This may be related to certain unique sources of my power. For that very reason, systematically learning how to perceive, absorb, and balance Natural Energy is, for me, completing an important piece of the puzzle, allowing me to more fully understand the power system of this world, and perhaps... find a way to fuse different power systems and create new possibilities."
He looked at Katsuyu Sage, his attitude sincere: "Therefore, Katsuyu-sama, I hope to follow you and systematically learn the Sage Arts of Shikkotsu Forest. Starting from the most basic perception of Natural Energy."
Katsuyu Sage gazed at Menma.
It could sense the sincerity in this young man's words, and his pure desire to explore for the essence of knowledge and power, rather than greed.
This was different from many other contractors who would stop at nothing for power.
'The last time I had seen a human like this seemed to be that man named Senju Hashirama.'
"Heh heh... You are indeed interesting." Katsuyu Sage's voice was as gentle as ever, even carrying a hint of appreciation. "The Sage Arts training of Shikkotsu Forest differs from that of Mount Myoboku and Ryuchi Cave. We focus more on 'fusion' and 'symbiosis', emphasizing the harmonization of body and mind with the rhythm of nature. The process may be more gradual, but the foundation is more solid. Since you sincerely seek instruction, and I..."
Its mountain-like body stretched slightly, stirring a damp breeze.
"Do indeed look forward to the forest you promised where I can stretch freely... then, let us begin."
Over the following period, in this silent and ancient alternate space of Shikkotsu Forest, a teaching session officially began.
Katsuyu Sage's first instruction was 'stillness'.
It had Menma find a relatively dry stone to sit on, discard all distracting thoughts, shut down active seeking of external stimuli like vision and hearing, and instead turn his attention completely inward to the most subtle life rhythms within himself.
Heartbeat, breathing, blood flow, every spontaneous circulation of Chakra.
This was not ordinary meditation, but rather contracting perception inward to its extreme, to experience the most fundamental 'kinetic energy' that sustains life.
"Natural Energy is not a distant, external object. It precedes your consciousness and has long been participating in the cycle of life within your body. What you need to do is not 'search' for it, but first 'recognize' it." Katsuyu Sage's voice was like a babbling brook, guiding Menma's consciousness.
Menma followed its instructions.
Given his current spiritual power and the precision with which he controlled his own abilities, this was not difficult.
Soon, after excluding active Chakra fluctuations, he 'saw' some deeper things.
The faint, firefly-like glow of life during cell metabolism, the subtle sparks of nerve signal transmission, even the ripples of constantly arising and ceasing thoughts deep in his consciousness...
Beneath all of this, there seemed to be a background 'frequency' like the pulse of the earth. It supported everything, yet was almost obscured by all the more active 'processes'.
"Do you feel it? That seemingly 'still' foundation that supports all 'motion'?" Katsuyu Sage's voice sounded at the right moment.
Menma did not answer, his entire focus immersed in this peculiar perception.
He attempted to slightly shift a sliver of attention away from his active life energy fluctuations, to touch and align with that deeper 'frequency'.
At first, nothing special was felt.
But as time passed, under Katsuyu Sage's spiritual guidance, which carried a certain rhythm, Menma gradually felt that his own clear individual life boundary seemed to begin... to blur.
A wisp of slightly cool, moist, vibrant yet immensely peaceful energy, for the first time so clearly, through the pores of his entire body, through the gaps of his spiritual perception, quietly seeped in.
It was not like Chakra, which could be clearly guided and controlled. It was more like an 'invitation', a kind of 'assimilation'.
If you relax and resonate with it, it naturally converges upon you. If you are tense and try to forcibly grasp it, it slips away like water through your fingers.
This is Natural Energy!
Different from any nature-affiliated Chakra, it is more primitive, more inclusive, and more 'willful'.
Menma did not rush for success.
He carefully remembered Katsuyu Sage's teachings, maintaining that state of 'contemplative observation' and 'resonance', allowing those wisps of slightly cool Natural Energy to penetrate his body, slowly contacting his own active Physical and Spiritual Energy.
At first, the two were distinctly separate, even slightly repelling.
But Menma, relying on his strong spiritual control, patiently adjusted the 'frequency' of his own two energies, gradually bringing them closer to and harmonizing with the penetrating Natural Energy.
This was an extremely delicate process, requiring absolute focus and meticulous control over one's own power.
One slight misstep, an imbalance in the ratio, and the Natural Energy would overwhelm the host, causing backlash and making the body gradually 'naturalize'.
Like the petrification of Mount Myoboku.
But Menma's soul strength and spiritual power far exceeded ordinary people. Under the safe and peaceful guidance methods coalesced from Katsuyu Sage's thousand years of experience, although the process was slow, it steadily advanced.
No one knew how long passed.
Shikkotsu Forest had no sun or moon, only eternal mist and dim light.
Finally, in the place where Menma's Chakra converged, a wisp of extremely subtle, yet completely different in nature brand new energy slowly came into being.
It was more 'agile' than ordinary Chakra, carrying a trace of the wild, expansive aura of nature, yet perfectly fused with his own life, responding to his will as if it were part of his arm.
The first wisp of Senjutsu Chakra had been successfully refined!
Menma slowly opened his eyes. Deep within his pitch-black pupils, a gleam of the crystalline moisture belonging to nature seemed to flash briefly.
He raised his hand, and above his palm, a thin strand of Chakra with a faint, crystalline greenish tint silently appeared, swaying slightly, resonating wonderfully with the environment of Shikkotsu Forest, as if it were a part of this very world.
Menma had successfully taken the first step.