Upon hearing about Natural Energy, Naruto immediately thought of Sage Mode—and the Ten-Tails.
After the Fourth Shinobi World War, some secrets were no longer secrets.
The Ten-Tails absorbed Natural Energy and converted it into Chakra, which was how so-called ninja came to exist.
The toads of Mount Myoboku also knew how to use Natural Energy, which led to Mount Myoboku becoming one of the Three Great Sage Regions.
The other two sacred regions, Ryūchi Cave and Shikkotsu Forest, likewise possessed Sage Art traditions.
Thinking of this, Naruto seemed to understand something.
At that moment, Mei continued, "Natural Energy is remarkably mysterious. Ninja who know how to use it become far stronger, while toads, snakes, and slugs that know how to use it have undergone evolution—they can speak, use Ninjutsu, and possess intelligence no less than that of humans."
"And then there is the Ten-Tails, known as the aggregate of all Tailed Beasts. Its very existence is for absorbing Natural Energy. But the Natural Energy in this world is limited. If the Ten-Tails absorbs too much of it, not only will the land wither, but every living being on earth will lose the possibility of evolving."
Having said that, Mei looked toward the Great Toad Sage. "Am I right?"
"Very right." The Great Toad Sage unusually straightened up. "So Shiraishi Yoshijo's so-called evolution is the absorption of Natural Energy?"
"More precisely, it is the conversion between different forms of energy. Your ability to use Natural Energy does not mean you truly understand it. The one who truly understands Natural Energy is me, the Butterfly Sage, who is proficient in energy manipulation. Natural Energy can produce Chakra of all attributes, so Chakra of all attributes can likewise be combined into Natural Energy."
Mei suddenly cut herself off, revealing a cold smile. "You