Black Zetsu felt he had to observe Kazuki again.

Originally, Black Zetsu didn't think Kazuki would cause any trouble for his plan, he was just a slightly more talented Uchiha, and Black Zetsu had seen many such geniuses over the past centuries.

However, Kazuki ultimately had no siblings, making it impossible for him to awaken the Eternal Mangekyo Sharingan.

Nowadays, the Uchiha clan's bloodline had degenerated to the point where awakening the Mangekyo Sharingan was extremely difficult.

Even if one awakened the Mangekyo Sharingan, they would still need to consider completing their own eyes, which would involve fusing another pair of Mangekyo Sharingan that perfectly matched their own.

Kazuki actually had such a pair of eyes, those belonging to Kagami. But since this pair of Mangekyo Sharingan was in Madara's hands, it was impossible for them to fall into Kazuki's possession. This meant that even if he awakened the Mangekyo Sharingan in the future, and some contemporary Uchiha, with immense luck and talent, also awakened the Mangekyo Sharingan, Kazuki would still be unable to awaken the Eternal Mangekyo Sharingan.

Although no one had ever tried, Black Zetsu was the most knowledgeable about the Uchiha in this world. If two pairs of Mangekyo Sharingan were incompatible and couldn't complement each other, they couldn't form the Eternal Mangekyo Sharingan.

In fact, at the very beginning, there was no such thing as the Mangekyo Sharingan, let alone the Eternal Mangekyo Sharingan.

Kazuki hadn't left Konoha much in the past two and a half years, which prevented Black Zetsu from paying attention to him. Previously, he didn't know how far Kazuki had grown, but now that Kazuki had defeated Hanzō, Black Zetsu started to care.

A ten-year-old Uchiha defeating Hanzō? Could he have already awakened the Mangekyo Sharingan?

Also, he wondered if Kazuki was connected to Indra. His gaze subtly shifted towards Madara's eyes, thinking that after Madara's death, he might be able to guide Kazuki to obtain those eyes and then help Kazuki acquire the Eternal Mangekyo Sharingan, making him a backup eye for the future.

Kazuki was also a decent combat force.

As for whether he could successfully trick Kazuki? Wasn't that simple? With the Uchiha clan's intelligence, wasn't it always a sure thing when he tricked them?

Indra himself was tricked by him back then, and Madara was currently proceeding according to his plan, so Kazuki would probably be easy to trick as well.

"Kazuki?"

Madara pondered for a moment but couldn't recall the name. Clearly, he genuinely didn't care much about Kazuki.

Before Nagato matured, Madara had no intention of finding his own agent within the Uchiha clan.

Black Zetsu explained, "He's Kagami's son, Tsunade's disciple, but he seems to have been taught by Mito."

"This time, he defeated Hanzō. As for how he defeated him, I need to go investigate."

"Alright, go take a look."

Madara didn't care about Kagami's matters. In his opinion, he had merely obtained a good pair of eyes.

As for Kagami, although he had awakened the Mangekyo Sharingan, he wasn't very intelligent, becoming a disciple of Tobirama. Wasn't that disgracing the Uchiha?

Where was the Uchiha's pride? Moreover, Tobirama had killed Izuna. Could these Uchiha really let go of their hatred?

Although Madara had also let go of his hatred for Hashirama back then, that was only the case for Hashirama, he still harbored hatred for Tobirama.

Kazuki was Tsunade's disciple and was raised under the tutelage of Mito. Could he be another Kagami?

This made Madara very uncomfortable. Perhaps he should eliminate this brat too.

A teenager in his teens could defeat Hanzō. Could he have awakened the Mangekyo Sharingan?

The Mangekyo Sharingan wasn't invincible, but some dōjutsu were indeed powerful. Some so-called strong individuals could be finished off if caught off guard.

...

Guided by White Zetsu, Black Zetsu saw Kazuki not far away, watching him wield the Sword of the Thunder God, traversing the battlefield with sparks and lightning. Any ninja who encountered Kazuki would instantly lose their life. Black Zetsu fell silent.

Kazuki wasn't using the Mangekyo Sharingan, it was clearly only a three-tomoe Sharingan. But looking at the aura around Kazuki, it seemed he had mastered Sage Mode.

Black Zetsu was aware of Sage Mode, but he had never contacted the Three Sage Regions. The Ōtsutsuki clan and the so-called Three Sage Regions were almost in a death feud.

At the same time, Black Zetsu was also very wary of the so-called Three Sage Regions. No one knew if they would discover him.

If they could contact his elder brother, that would be terrible. He didn't believe that Hagoromo was truly dead.

Before rescuing his mother, his identity absolutely could not be exposed or discovered.

Black Zetsu had seen the power of Sage Mode on Hashirama, it was a very powerful technique.

He hadn't expected Kazuki to have learned it.

Most importantly, he felt a familiar aura on Kazuki, it was definitely Indra Chakra without a doubt.

As Kazuki's strength further increased and his Sharingan enhanced, the aura belonging to Indra gradually became apparent.

His guess was indeed correct. Indra Chakra had split himself.

So, should he cultivate Kazuki? If not, then he needed to eliminate him as soon as possible.

None of Indra Chakra's reincarnations were simple.

If Kazuki were allowed to grow, no one knew what level he could reach.

However, Kazuki was still worth investing in. If he were to lose his sight in the future, then he would have a chance to lead him into the abyss.

Could the Uchiha clan also learn Sage Mode? This was the first time he had known this.

And looking at Kazuki's current state, apart from Madara, there were probably very few ninjas in the Ninja World who could challenge Kazuki.

...

"Madara, Kazuki has learned Sage Mode and also Tobirama's Flying Thunder God Technique."

After returning to the underground vault, Black Zetsu quickly reported to Madara.

"Tobirama's Flying Thunder God Technique?" Madara frowned.

Who would normally learn the Flying Thunder God Technique?