Of course, Kazuki's acceptance of Natural Energy was also better than initially expected. Perhaps this was related to Kazuki becoming more and more like a member of the Otsutsuki clan.
Although his arm softened after Natural Energy was injected, appearing as if the Natural Energy had gone wild, it was still barely within his acceptable range. As long as he didn't act recklessly, he could ensure he wouldn't be affected by this Natural Energy.
One could even say that he no longer needed Katsuyu to give him specific guidance, and besides, Katsuyu had never guided Kazuki in learning Sage Mode before.
Sharingan was an unstable factor for Sage Mode.
Kazuki had maintained this state for over three months. During these three months, he had been researching Natural Energy almost constantly, apart from his usual eating, sleeping, and resting.
He had thought about using the Combat Arena to extract the Sage Mode of Naruto, Hashirama, and Kabuto.
Unfortunately, the opponents recently spawned in the Combat Arena weren't very strong. Even if he defeated those relatively powerful opponents, he only obtained one or two of their Ninjutsu.
For the current Kazuki, ordinary Ninjutsu could no longer significantly increase his strength, though his Chakra had increased by three units due to the Combat Arena.
This scene made Katsuyu silent. Such a rapid growth in Chakra was a bit fast.
However, as the reincarnation of Indra Chakra, wasn't it normal for Kazuki to have such growth?
Kazuki's three-tomoe Sharingan spun faster and faster, and the Chakra fluctuations around him intensified, making it impossible for Katsuyu to relax about Kazuki for even a moment.
It always felt that Kazuki was playing with fire. Was Natural Energy that easy to familiarize oneself with?
Since Sage Mode couldn't be learned in a short time, Natural Energy was problematic after all. If any accident occurred, he could die.
Who would learn Sage Mode by constantly adapting their body to Natural Energy?
In Katsuyu's view, this was a crazy idea, but if truly considered, it did have some theoretical feasibility.
It was just that no one had ever succeeded before, as it demanded too much from the learner.
Finally, Kazuki's body began to change. His Sharingan became more enchanting, and a skeleton made of Chakra appeared around him.
"Is this Susanoo?" Katsuyu was shocked.
It wasn't that it hadn't seen Susanoo before. When the Uchiha clan and Senju clan fought, it often participated, after all, Katsuyu's summoning scroll was passed down through generations of the Senju clan.
Even Madara's Susanoo, Katsuyu stated that its clones had been hit by it.
Don't think that Madara's Susanoo is very powerful and it couldn't kill it. Katsuyu stated that it could fight Madara for a whole day.
As for the so-called genjutsu control, Katsuyu wasn't worried at all, okay? It had plenty of clones, could Madara control all of them?
But what was going on with Kazuki?
Activating Susanoo with a three-tomoe Sharingan, even if it was only the first stage of Susanoo, made Katsuyu think of a legendary figure.
It had seen the other party back then, and that person had saved the Ninja World.
Unfortunately, its connection with that person wasn't deep, mainly because Mount Myōboku and Hagoromo had a good relationship.
However, Katsuyu had a good relationship with Asura and had always maintained a good relationship with the Senju clan afterward.
After three months of interaction, Katsuyu also discovered that Kazuki's bloodline might have already begun to revert to its ancestral form. He faintly had a trace of Asura's bloodline aura.
It wouldn't suspect that Kazuki had a special cheat that allowed him to possess the physique of the Senju clan and Uzumaki clan, such an example had never appeared before.
Instead, the phenomenon of bloodline reversion occasionally appeared in other clans, it's just that this was the first time it had appeared in the Uchiha clan.
Considering this was the first time such a situation had appeared in the Uchiha clan, and Kazuki was also the reincarnation of Indra Chakra, Katsuyu was full of expectations for Kazuki.
Perhaps Kazuki would surpass Madara in the future.
'It seems to be Susanoo, but I don't seem to have awakened any other dojutsu.'
Kazuki looked at the pond water beside him, and through the reflection, he saw that his eyes were still three-tomoe Sharingan. He was clearly stunned for a moment.
'Can I activate Susanoo without awakening the Mangekyo Sharingan?'
Kazuki could clearly feel that his ocular power had significantly improved, but he still didn't seem to have awakened the Mangekyo Sharingan, nor had he acquired any Mangekyo Sharingan dojutsu.
However, Susanoo was indeed activated, so what did this mean? A half-step Mangekyo Sharingan?
However, after activating Susanoo, he didn't have the full-body soreness that Sasuke mentioned. His eyes had a slight ache, but he felt that his ocular power hadn't decreased.
Was this because he had absorbed too much ocular power and his physique, under the nourishment of Natural Energy, had become like Hagoromo?
Kazuki's mind stirred. He tried to make his Susanoo grow and transform into the second stage, but in just an instant, he gave up.
He could activate it, but it would be very strenuous and might even damage his eyes. It would be better to wait until his ocular power was stronger in the future before activating a higher stage.
"Actually, there was no such thing as the Mangekyo Sharingan initially, but I didn't expect you to be able to activate the Susanoo without awakening the Mangekyo Sharingan. This is not a bad thing, no need to worry." Katsuyu observed Kazuki for a while before speaking.
"Moreover, your Sharingan is linked to your Yin Release Chakra."
"If your Yin Release Chakra is too vast and far stronger than your physical strength, it might cause damage to your body."
"Your current body is already much stronger than many adult Uchiha, but you are still only ten years old, so there is no need to urgently upgrade your Sharingan."
"I understand. Thank you."
Kazuki thought of the future Itachi, who developed a Kekkei Genkai illness because he awakened the Mangekyo Sharingan too early.
Many people said that Itachi held back a lot, but in reality, at that time, even if Itachi didn't hold back, could he unleash his full strength?
He even had difficulty dodging shuriken. It was already a struggle to exert 50 or 60% of his power.
Can you expect a person who is terminally ill to unleash their full strength?