Hiruzen persuaded me to die

During the Fourth Great Ninja War in the original timeline, Uchiha Madara used the Yin-Yang black rods to absorb senjutsu chakra from Hashirama Senju.

Since senjutsu chakra could be transmitted through the black rods, and natural energy was part of senjutsu chakra, it meant natural energy itself could also be transmitted through Yin-Yang Release black rods.

Even though Madara hadn't mastered Sage Mode at that time, he still relied on Yin-Yang black rods inserted into Hashirama's body. And even when he couldn't control the chakra, if the natural energy ran wild, the black rods allowed it to be transmitted back into Hashirama's Edo Tensei body.

In other words—

For those capable of creating Yin-Yang black rods, there was almost no risk when practicing Sage Mode in this way.

"Amazing... The natural energy is transferring into the clone," Katsuyu said with genuine awe as she observed the petrified Wood Clone.

With this technique, training in senjutsu carried no danger.

If one absorbed too much natural energy, causing it to go berserk, they could simply reroute it into the Wood Clone through the black rod!

"Yin-Yang black rod?" Tsunade tilted her head, her expression confused.

She had some understanding of Yin-Yang Release.

Her own medical ninjutsu, after all, stemmed from Yang Release.

According to legend, Yin-Yang Release had the power to create something from nothing—the ultimate chakra transformation.

Hyuga Naraku glanced at Tsunade and summoned a slender black rod into his palm.

"If you want to try learning Sage Mode again, this will keep you safe."

"Just pierce this black rod into your body."

"If the natural energy goes wild, I'll extract it directly from you."

Tsunade: "..."

Why... why does that sound so weird?

But still...

Tsunade couldn't resist the temptation of Sage Mode.

After hesitating for a second, she took the black rod and inserted it into her shoulder.

In that instant, a strange connection formed between her and Naraku.

Tsunade frowned slightly.

Why did she feel... like a puppet?

It was as if Naraku could completely control her through that rod.

Still, she said nothing.

On Katsuyu's side, the formal teaching of senjutsu had begun.

"To refine senjutsu chakra, you must balance your body's chakra with natural energy," Katsuyu explained seriously.

"Specifically, that means balancing physical energy, spiritual energy, and natural energy. These three form chakra, and they must coexist in harmony."

"But that balance isn't a simple 1:1 ratio," she added, swaying her tentacles as she spoke.

"Everyone's chakra has different traits. That also means their physical and spiritual energies differ in strength."

"For instance, the Senju and Uzumaki clans possess especially strong physical energy. Meanwhile, the Uchiha and Hyuga clans tend to have stronger spiritual energy."

"To successfully merge chakra and natural energy, you must adapt to your own body's traits."

Naraku nodded slowly, thoughtful.

In a way, chakra was like a ninja's genetic signature.

Each individual had a unique balance between their physical and mental energies.

The chakra formed from their combination had different affinities and attributes.

For example, Uchiha chakra had a chilling quality—cold, sharp, and intense.

Even between close individuals, chakra signatures varied subtly.

With enough sensitivity, one could identify someone by chakra alone.

"But in the end... shouldn't the three energies be roughly balanced in volume?" Naraku asked.

If so, then activating Sage Mode would only give a 1.5x boost in chakra.

That felt… underwhelming.

After all, the battle between Hagoromo Ōtsutsuki and Kaguya lasted for months.

Kaguya had the Ten Tails—so her enormous chakra reserve made sense.

But how did the Sage of Six Paths fight for so long?

Naraku had always suspected the secret lay in senjutsu.

"When synthesizing senjutsu chakra," he asked, "what role does your regular chakra play?"

"If you don't use your own chakra... can natural energy be used on its own?"

Katsuyu blinked in surprise, then quickly recovered.

"That's a very insightful question."

"I've tried many ways to use pure natural energy directly—but none of them worked."

"You must include your own chakra in the mix. Otherwise, natural energy can't be used effectively."

Naraku narrowed his eyes.

"So, could we say that our chakra is a kind of 'primer'... or a catalyst?"

Natural energy existed endlessly across the world—an invisible force between heaven and earth.

But to use it required an intermediary—a key.

And the best key ever devised was something the Ōtsutsuki clan discovered:

The Ten Tails.

The God Tree.

The Ōtsutsuki had planted God Trees on countless worlds, all to absorb natural energy and condense it into chakra fruit.

Clearly, even to the Ōtsutsuki, chakra was more usable than raw natural energy.

If they couldn't directly use natural energy efficiently, it was even harder for ordinary humans.

"That may be the case," Katsuyu agreed.

"The more you master senjutsu, the more natural energy you can control with the same amount of chakra."

Naraku gave a thoughtful nod, then asked another question.

"The Sage of Six Paths came to the Shikkotsu Forest after Kaguya was sealed, right?"

"Did he study senjutsu here?"

Katsuyu responded with a nod. "Yes."

"He shared stories of the outside world, and in return, I taught him our forest's sage arts."

As she spoke, something seemed to jog her memory.

"Your First Hokage also trained in senjutsu here."

"Later, he even modified the method on his own."

"He told me his version only worked for him."

Naraku couldn't help but marvel. "That's so like Hashirama."

Always laughing and acting clueless… but his natural talent was frightening.

It made sense now.

Even Hagoromo, after learning Mount Myōboku's sage arts, came to the Shikkotsu Forest for deeper mastery.

Eventually, he developed his own legendary Six Paths Sage Mode.

"You're getting way ahead of yourself."

"Shouldn't you actually learn Sage Mode first, before you start comparing yourself to the Sage of Six Paths?"

Tsunade interjected with a smirk, unable to hold back.

She couldn't believe it.

He hadn't even completed Sage Mode yet, and he was already theorizing like a heavenly scholar!

"You're a little too confident, aren't you?"

Honestly, it'd be pretty embarrassing if he failed after all that talk.

"If it's just about balancing the three energies, I think I've got it."

Naraku replied calmly.

As he spoke, he clapped his hands together.

A massive wave of natural energy surged toward him, as though responding to a divine call!

"Sage Mode—activate."

Naraku murmured.

Instantly, a powerful aura exploded outward from his body.

The dark clouds above, once swirling with acidic rain, suddenly scattered.

Brilliant sunlight pierced the sky, shining down on the earth like a divine revelation.

End of Chapter 168