Space-Time Mission

If the Sharingan was a major cheat in the early story, then in the later stages, where power scaling went off the rails and overpowered characters were everywhere, the Rinnegan could definitely hold its own.

What was it like to have the Rinnegan early on?

Just look at Nagato wiping out Konoha single-handedly!

If Naruto hadn't returned in time, Konoha might really have been destroyed!

"Exchange!"

Uchiha Kei didn't hesitate for a second.

But the system's next prompt left him dumbfounded.

"Ding! The Rinnegan is a Six Paths-level jutsu. It can only be exchanged after completing a Space-Time Mission. Do you wish to proceed?"

Uchiha Kei froze. A Space-Time Mission? What kind of bizarre thing was that?

He didn't understand what a Space-Time Mission was, but compared to the immense power the Rinnegan offered, it didn't matter at all.

"Proceed!"

"Ding! The host has agreed to undertake the Space-Time Mission."

"Space-Time Mission activated."

"Space-Time Mission: Return to the Warring States Period."

"Space-Time Mission requirements: Within 30 days, take Senju Hashirama and Uchiha Madara as disciples, and raise both of their abilities to the level of an elite jonin."

"Space-Time Mission enhancements: Absolute Defense; enhanced Mangekyō Sharingan abilities, with unlimited use of Uhijini; exclusive ability—Bloodline Enhancement."

"Space-Time Mission modification: Host's age set at 20."

"Mission reward: Six Paths jutsu—the Rinnegan."

"Time Reversal."

In an instant, Uchiha Kei felt a powerful force pulling at him. A deep blue door appeared out of thin air.

Without hesitation, Uchiha Kei stepped through.

The moment he entered, the deep blue door vanished into thin air.

At the Hokage Building.

Sarutobi Hiruzen, who had been relaxed just moments earlier, sprang to his feet. His entire body tensed as he released every last bit of his Kage Level chakra.

"What a strange power. Has someone come to Konoha?"

Sarutobi Hiruzen's face turned grave as he stared intently out the window.

At the same time, the heads of the major clans and Danzo all turned their attention toward Konoha.

Konoha was gripped by alarm!

Uchiha Kei had no idea how much commotion his journey through time had caused in Konoha.

After he stepped through the door, a lush forest appeared before him. Several animals spotted the sudden appearance of a human and fled in fright.

"So this is the Warring States Period?"

Uchiha Kei curiously looked around.

From the Warring States Period through the founding of the Ninja Villages and the Second and Third Shinobi World Wars, the Naruto World had been ravaged beyond recognition. Scenery this pristine was long gone.

For one thing, many of the animals he saw no longer existed.

"Y-you... who are you?"

A watermelon-haired boy stared at the young man who had appeared, his face filled with fear.

Uchiha Kei turned around and saw the boy.

Had he really found one of the main characters this quickly?

Senju Hashirama!

Uchiha Kei walked up to the boy and asked, "Hey, kid, are you Senju Hashirama?"

Young Senju Hashirama looked wary and took a few steps back. "Yes, I'm Senju Hashirama of the Senju Clan. How do you know my name?"

The kid was pretty cautious.

But Uchiha Kei understood. In the war-torn Warring States Period, a battle could break out at any moment. Anyone who wasn't wary would be a fool.

"My name is Kei. You can call me your teacher."

Uchiha Kei looked at young Senju Hashirama with a beaming smile.

At this point in his life, Senju Hashirama wasn't interested in getting stronger. He was famously useless among the Senju Clan, and far too naive for his own good.

If his father weren't the clan leader, someone like him would have struggled to survive in the chaotic Warring States Period.

"Teacher?" Senju Hashirama stared blankly at him. "How can I call you my teacher? I'm not your student."

"Then why not become my student?"

"Well, I guess that makes sense. Then I can call you teacher."

Hashirama's airheaded nature was on full display.

"No, wait! I don't even know who you are. Why should I become your student?"

Hashirama might have been airheaded, but he wasn't stupid. After thinking it over, he realized something was off.

"I told you, my name is Kei."

Uchiha Kei smiled as he walked up to Hashirama and placed a hand on his head.

"I can help you make your wish for peace come true."

"Peace... can it really come true?"

Hashirama instinctively tried to dodge, but Uchiha Kei's words caught his attention, and for a moment he forgot to move.

"Of course it can..."

Uchiha Kei was about to say more when he sensed something. A smile tugged at his lips.

"Hey! Let him go!"

A spiky-haired boy raced over from the other side, glaring coldly at Uchiha Kei.

"Madara!"

Hashirama smiled happily and started to pull away from Uchiha Kei so he could run over.

"Don't move!"

The spiky-haired boy shouted.

Hashirama was too airheaded to notice, but Madara saw it clearly.

The young man with a hand on Hashirama was terrifying!

He could feel an indescribable aura moving around the young man.

Even his own father couldn't compare!

"Who are you? Let Hashirama go! I'm warning you, he's the heir to the Senju Clan!"

The Senju Clan and the Uchiha Clan were both renowned, powerful clans in the war-torn Warring States Period.

Ordinary people gave both clans a wide berth.

"I know," Uchiha Kei replied calmly. "I also know you're Uchiha Madara, the heir to the Uchiha Clan."

"You..."

Just then, the ground shook violently, and countless birds and beasts burst into flight.

Uchiha Madara's expression changed. He shouted at Senju Hashirama, "Hashirama! Run!"

As soon as the words left his mouth, a massive tiger with vivid stripes and a powerful stench of blood appeared in their line of sight.

"Roar!"

The tiger eyed its prey hungrily and charged forward with a thunderous roar.

Uchiha Madara and Senju Hashirama both darted north.

Uchiha Kei watched the tiger with interest.

Once the Ninja Villages were established, these giant beasts had been almost completely wiped out to keep the villages safe.

He was naturally curious to see one now.

These naturally born beasts had no chakra or jutsu. They relied entirely on their bodies and instincts to attack.

Yet in the Warring States Period, beasts like these inflicted devastating losses on the shinobi.

"Roar!"

The tiger raced up to Uchiha Kei, then abruptly stopped and stared at this "prey" uncertainly.

Its instincts told it the "prey" before it was dangerous, radiating an aura that made it uneasy.

"Little guy, are you scared?"

Uchiha Kei wasn't worried in the slightest.

The system had said he had Absolute Defense. He wasn't afraid of even a fully grown Senju Hashirama or Uchiha Madara, so why would he fear a big cat?

What a joke.

"Yowl!"

The tiger flinched.

Where had this guy come from? Why was he so terrifying?

"Y-you need to run! This thing could kill even a Chunin!"

Somehow, Senju Hashirama had come running all the way back. He grabbed Uchiha Kei and tried to drag him away.

Unfortunately...

He couldn't move Uchiha Kei at all!