As stated in the mural, this Three Great artifact is a Spiritual Item which exists in Susanoo.
When Mangekyō Sharingan is able to use Susanoo to a certain level, it will have the ability to use this kind of artifact, just like Itachi's Yasaka Magatama, that in fact is using the power of Yasaka Magatama.
"The power of Susanoo is really enviable, but it seems difficult to use it only with one eye." Kakashi then said.
In the original work, after his right eye is taken away by Danzo, Shisui was still able to use Susanoo with a single eye, and Uchiha Madara was more awesome as he could use it without any eyes at all.
In other words, when Mangekyō is opened, the user would be able to use Susanoo.
The key to use Susanoo is the Mangekyō Sharingan, and once the user has opens the Mangekyō Sharingan, they would be able to use Susanoo even without both of their eyes.
But unfortunately, Kakashi is not the original owner of the Sharingan.
So at this time, Kakashi can't use Susanoo at all.
At the original work, Kakashi is able to use Susanoo because Obito gave his other eye. And his Susanoo is amazingly powerful, but it is only a short-lived.
Kakashi can only envy this ability for now.
This place actually has the information of Three Great Artifacts, and there is also the existence of Rashomon, which makes Kakashi curious about the one who create this place.
But speaking of the powers of the Three Great Artifacts, Itachi's Susanoo's equipment is really enviable.
Its right hand is holding Sword of Totsuka, its left hand is holding Yata Mirror, and it is also able to use Yasaka Magatama.
With such artifacts at hand, his Susanoo is really scary.
Perhaps it is one of the reasons why Itachi is seriously ill.
After digesting these amazing news slowly, Kakashi did not stay here much longer.
This place is not very valuable for Kakashi, even if he found Rashomon Gates, it is useless for Kakashi.
Kakashi then turned and left. Soon, he arrives at the entrance of the cave.
Seeing Kakashi coming out, Nanairo hurriedly stepped forward and asked: "Kakashi, how is it? What's inside?"
"There is Five-Layer Rashomon, but the contract scroll is gone so it cannot be used at all."
Kakashi did not hide anything, and directly told Nanairo about what he saw.
Nanairo was a little disappointed when he heard this. He didn't expect the so-called forbidden land to be like this.
"Nanairo, what are you going to do next? Rebuild Hell Valley?"
"Hell Valley is bound to be rebuilt, but it is still too early. After I get my revenge, I will rebuild Hell Valley."
"Okay, when the time comes. I'll help you."
"Thank you."
"It's okay, I am your companion now, so this is what I should do."
Nanairo looked at Kakashi and he seemed to be moved by Kakashi's words.
"Okay, we should go back now."
"Yeah."
The Hell Valley matter came to an end, and Kakashi didn't plan to stay here any longer.
After all, this place is too close to the Land of Rain.
So there is a lot of danger.
At Mount Myōboku, a silhouette suddenly appeared.
Silver-white hair, black clothes, it is no other than Kakashi.
After handling all of his affairs, Kakashi came to Mount Myōboku.
Improving his strength is the most important thing for Kakashi right now, and naturally it can't be delayed.
As soon as Kakashi arrived, he saw a familiar figure.
"Fukasaku-sama." Kakashi called respectfully.
He knows that this little toad contained terrifying power.
"Ah, Kakashi-chan, you are finally here, why did you take such a long time?"
"Sorry, there are some things I need to do first."
"Okay then, let's get started. The Cursed Seal on your neck has been eroding your body. So if you don't solve it early, it will be very troublesome."
"Yeah, I understand."
"Then let's get started, come with me."
Fukasaku said, as he starts moving. Kakashi then follows him into a Waterfall with brown liquid.
"Kakashi-chan, before you learn Sage Mode, I have to tell you what Natural Energy is. The so-called Sage Mode is actually to absorb the Natural Energy from the nature."
"We all know that the so-called Chakra is formed by the fusion of the body Spiritual Energy and the Physical Energy, and Senjutsu adds the Natural Energy on top of foundation. These three must be kept in balance, that is, the amounts of each of them need to be one third."
"And if the distribution is very unbalanced, you will become a stone frog. You see there are so many stone frogs here, they all become like this because they failed to control the Natural Energy. If there is only a little imbalance of Natural Energy, you still can also use Sage Mode, but your body will have some of the frog feature, Jiraiya-chan is now in this situation."
"Sage Mode can only be practiced by someone who has a huge chakra reserve. Otherwise, it is impossible to control the violent Natural Energy. The more the chakra reserve, the better they will be at practicing Sage Mode. Of course, this is only part of the reason. Like Jiraiya-chan, his Chakra is very huge, but his talent on Senjutsu is not so outstanding that even after training it for a long time, he still can't perfectly use the Sage Mode."
"Minato-chan has also learned Sage Mode. His talent is much better than Jiraiya-chan. Although his speed to enter Sage Mode is very slow, his state after entering it, is much better than Jiraiya-chan."
"Kakashi-chan, although your chakra reserve is still not as large as Jiraiya-chan, you can still train in Senjutsu as your Chakra reserve is enough. As for whether you can successfully learn it or not, it depends on your own effort."
"I understand, Fukasaku-sama. Then what should I do next? How do I absorb this Natural Energy?"
"Natural Energy is very hard to sense, so the first step in practicing Sage Mode is to stay still!"
"Stay still? So I need to not moving?"
"Yes, you need to stay still. You see, this brown waterfall is the unique oil of Mount Myōboku, which can help you to feel the Natural Energy more quickly."
"So it's like that. Then will we start now?"
"Yeah, I will apply this oil on your body later. If you can't control the Natural Energy, I will use this stick to knock out all the Natural Energy from your body."
Fukasaku said as he took out a black stick.
"Okay, let's start now."
Kakashi said as he took off his shirt, revealing his thin but muscular upper body.
There is a red tattoo on his left arm, which is the symbol of Anbu.
"Well, let's get started. Kakashi-chan, you need to be very patient, I hope you can hold on."
"Don't worry Fukusaku-sama, my best virtue is patient after all."
Kakashi said as he sat down cross-legged.
Fukasaku takes some oil and splash it directly on Kakashi's body.
Kakashi only felt that his body was cold, and a very strange feeling came to his mind.
The nature seems to be quiet in an instant, and Kakashi can feel that there is a formidable Strength that gets into his body through the body part that is splattered by the oil.
And his body seems to be undergoing a very strange change.