In her original plan, she intended to refine the natural energy sealed in her forehead, then fuse it with her Ōtsutsuki chakra to generate new sage chakra.
However, something unexpected occurred in the process.
The vast amount of natural energy she had absorbed from the Tenryū Heart Cave was incompatible with the natural energy of her current location. The two types of energy repelled each other.
In other words, it was as if she had absorbed natural energy from Ryūchi Cave but then went to Mount Myōboku to train in Sage Mode.
Satsuki temporarily stopped absorbing the local natural energy.
"Candle Nine Yin, do you have a solution?"
For matters she didn't understand, Satsuki never hesitated to ask.
"Let this old dragon have a look."
From the embroidery on Satsuki's robe, the great dragon form of Candle Nine Yin emerged. Fortunately, this sage land existed in a separate dimension—otherwise, such a massive body could never fit.
Candle Nine Yin roamed the hidden realm for a while, then used its sage sensory abilities to examine it before returning to Satsuki. "Lady Satsuki, the master of this sage land has already perished. This place now qualifies as an unclaimed sage land."
An unclaimed sage land?
"What does that mean?"
Satsuki paused her extraction of Tenseigan sage chakra and waited quietly.
"With Hamura's inheritance, I'm sure you're not unfamiliar with this world's truths," Candle Nine Yin began, coiling its immense body beside her. "We sages were the first lifeforms born in this world, and the first to learn to use natural energy."
Its tone darkened.
"But places in this world rich in natural energy are limited. These became what later generations call sage lands. To claim them, we sages fought countless competitions and battles."
This bit of dark history was unexpected, yet upon reflection, it made sense.
"To secure their claim, some sages developed a special sage technique: once they occupied a sage land, they would imprint their life signature into it. This would make the land's natural energy available only to that single species or those with related genetics. Later, their enemies discovered this method and spread it worldwide, so all sages marked their territories with such imprints."
Satsuki suddenly understood: no wonder only toads could train at Mount Myōboku, and those who trained in its Sage Mode took on toad-like traits.
The same was evident with Kabuto Yakushi after mastering Ryūchi Cave's Sage Mode.
"It's a form of certification—a declaration that this place has an owner."
Here, Candle Nine Yin shrank its body, holding two spheres of sage chakra in its claws.
One was golden, drawn from the Tenryū Heart Cave's natural energy; the other was blue, extracted from this sage land. Even at a glance, the difference was obvious.
"I have a question," Satsuki said. "You claim this is an unclaimed sage land, yet I've seen Shirakumaru's training records—he displayed obvious fish-like traits. Why is that?"
"Strictly speaking, I mean that its previous master is dead," Candle Nine Yin replied while circling in the air. "But unless an outsider alters the imprint, the natural energy will still bear that signature."
"I see." Satsuki's eyes narrowed. "Then how do I change the life imprint here?"
"You cannot do it alone," Candle Nine Yin said. "As an outsider of Ōtsutsuki blood, your lineage is not recognized by this land. You cannot perform a sage imprint."
"Alone, I can't…" Satsuki repeated, the light in her Tenseigan flashing as she looked at him. "But you can."
"Exactly, which is why I said you're truly fortunate," Candle Nine Yin laughed heartily. "This Candle Dragon body has a special connection to your Tenseigan chakra, and as its primary structure is formed from the Tenryū Heart Cave's sage chakra..."
"That makes it possible for it to be recognized by a sage land."
Candle Nine Yin gazed at the glowing orb in its claws with a hint of emotion. "I can use this Candle Dragon body's life imprint to mark this sage land. Through the Giant Tenseigan's authority, it will be as if this sage land recognizes you as its master."
"Then get on with it," Satsuki said, valuing her time. Once she understood the key, she had no need for delay.
"Alright." Candle Nine Yin's body erupted with intense sage chakra, forcing a drop of heart's blood from its tangible dragon form, mixing it into the vast sage chakra.
The sage chakra took the shape of a massive dragon, drifting in the air before locating the sage land's greatest source of natural energy. Its body turned into a beam of light and dove into the depths of the earth's veins.
A tremendous crash and a roaring sound echoed from deep below.
Through her Tenseigan, Satsuki saw the natural energy source take on the form of a giant carp in response to Candle Nine Yin's life imprint. The carp clashed with the dragon-shaped sage manifestation.
The difference in power was vast. The dragon quickly tore the carp imprint apart with one strike, then lunged at the source of the natural energy.
The tremors of the sage land ceased, and the surrounding natural energy shifted to a golden hue.
Candle Nine Yin returned to Satsuki's robe.
Through the Giant Tenseigan's link, Satsuki sensed a subtle yet profound connection between herself and this sage land.
"The sage land imprint is complete, my lady. The human body stores chakra in multiple places. Now that you've changed the imprint of this land's natural energy, you can use the yintang point on your forehead as another location to cultivate sage chakra."
Satsuki's eyes lit up at the suggestion.
In the original anime, there were multiple locations where ninja could store and extract chakra. The most common was the abdomen around the navel—used by the vast majority of shinobi.
But there were other points as well, such as the yintang point used in Tsunade's Yin Seal technique.
Satsuki's initial instinct to store the Tenryū Heart Cave's natural energy in her forehead had been influenced by this.
Yet while she could forcibly absorb such vast amounts of natural energy due to her own "hardware," extracting sage chakra from it had remained a problem.
Now, Candle Nine Yin had given her the key to solve it.
With her deep understanding of the human body, Satsuki knew there were actually three main chakra storage points:
The yintang point between the brows.
The guanyuan point, three inches below the navel.
The yintang could serve as a reservoir for natural energy and sage chakra, while the guanyuan was the seat of her Tenseigan chakra.
As for the newly fused sage Tenseigan chakra created through Candle Nine Yin's integration, it could be stored in the shanzhong point at the center of the chest.
This was Satsuki's plan for her future training.