I really don't want to answer the question of Chakra, but some people still take it out and mention it, and there is no way, the answer is actually already given in the comics.

Kakashi fought with Payne, and died because he ran out of chakra.

Chakra origin, Madara himself said that the origin of chakra is the sacred tree, and the sacred tree was brought to the earth from other places by the large barrel wood Kaguya, not the original thing of the earth.

The official setting also gives that Kalaya Otsuki is the first person on Earth to own, remember, the first person to own Chakra.

In other words, before the Otsuki Kaguya, there was no such thing as chakra on earth. It also proves that ancient humans did not have chakra and would not die.

But by the time of the original book, Kakashi would die from running out of chakra, emmmm......

Why chakra has become an essential energy for life on earth to sustain life is probably due to some unknown changes.

AB did not give an explanation or any explanation for these unknown changes, and could only rely on various personal brains to make up for guesses.

Personally, I tend to say that the earth underwent some kind of big change many years ago because of the planting of the sacred tree.

I don't know if there is a new explanation of Chakra in Boruto, because I have only watched a few episodes of Boruto and have not studied it deeply. The alien setting of the big barrel wood, I don't want to touch it deeply.

As for the darkness of the spirits collecting people's hearts, it makes more sense to use chakra for the setting here.

Chakra has the function of 'transmitting information', and the Six Dao Immortals have also said that he originally spread the Ninja Sect in the hope that human beings can communicate with each other under the guidance of Chakra and build a bridge where everyone can understand each other.

It can be seen that the chakra has a special channel of communication between the heart and the heart.

The sprite absorbs the darkness of the human heart, and must rely on the 'channel' to contact the human heart, otherwise it cannot be explained that the sprite absorbs the darkness of the human heart, and the sprite is truly invincible.

Therefore, it is set up here to absorb the dark part of people's hearts through the channel of chakra.

Once it severs its connection with Chakra, it loses its 'bridge' to the depths of people's hearts, and the darkness it grasps is useless.

For others, losing Chakra is death, but for Shiraishi, it's nothing more than relying on another energy to sustain life. This is a shadow of the ghost.

The basic structure is all given by the official, and I only added it in this book, and the spirit part of the second creation may be a little unreasonable. However, the origin of chakra comes from the fact that the sacred tree and the ancient humans did not have chakra, which is the original stuff in the official comics and settings. If these are denied, it can only mean that the Hokage's before and after settings have once again caused contradictions...... Why do you want to say again......

Anyone who understands understands.

Anyway, I don't believe that the third generation Hokage is the strongest Hokage.

Let Kakuto go to assassinate the first Hokage, and the brains of the high-level people in Takikuin Village must have been collectively kicked as a ball.