Starting as a Ninja in the Naruto World

"Feel it for yourself."

With a casual motion, Emiya Shigen placed a pitch-black curse mark on Senju Tobirama's arm. The mark even took the shape of Konoha's iconic swirling Uzumaki symbol.

"Chakra…"

"As expected, I can't channel it."

Tobirama raised his hand and attempted to use chakra, but the curse mark flowed through his body like a warm current, sealing his chakra and even causing his body to stiffen.

But…

Tobirama was, without a doubt, a ninjutsu genius.

The moment he realized he couldn't overpower the curse mark, he quickly adjusted his approach, allowing the curse energy to merge with his own chakra instead of resisting it.

"This power…"

A flicker of surprise crossed Tobirama's face.

The curse mark, infused with natural energy, significantly enhanced his strength when merged with his chakra.

Tobirama couldn't deny the truth:

Emiya Shigen's concerns about the curse mark causing future conflicts were valid.

If an ordinary ninja obtained a curse mark, they could potentially gain jonin-level chakra output. With proper training, they would become a formidable force on the battlefield.

The only issue was…

The curse mark wasn't easy to control.

Tobirama understood that his extensive knowledge of ninjutsu principles was the only reason he could quickly grasp how to manipulate the curse mark's energy. Even so, he couldn't fully master it.

Unfortunately…

Tobirama had made a promise to never use the curse mark for conflict.

He could only hope that Konoha's peace would last, so he wouldn't be tempted to use this power during desperate times.

"Let me help you remove the curse mark."

Emiya Shigen moved to undo the mark, appearing genuinely concerned that Tobirama's movements might remain restricted.

As he slowly formed hand signs, Shigen explained, "This basic use of natural energy is too easily learned. I only hope this power doesn't bring more wars to the world…"

"Lord Emiya."

Tobirama reached out to grab Shigen's wrist.

"There's no need to remove it just yet."

"I need to observe how the curse mark affects my chakra over time. I need to understand how long it can suppress my brother's chakra."

This ancient medical ninja is too naïve.

Perhaps, Tobirama thought, Shigen assumed that the ninjas of this era were as talented as those from his time.

Natural energy…

It's not that easy to master.

Tobirama had seen natural energy before.

His brother, Senju Hashirama, had mastered Sage Mode by harnessing natural energy. Tobirama had always been curious about it but lacked the innate talent to sense it himself.

He understood the value of this curse mark.

A slight pang of guilt flickered in his heart.

For Tobirama, power meant survival.

Power allowed him to gain control over uncertain situations.

Whether it was internal unrest in Konoha or external threats from rival villages, Tobirama couldn't afford to pass up any opportunity to strengthen his position.

He silently promised himself:

I will only use this power in the most desperate of times.

Of course…

There was no need to tell Shigen that.

"You and your brother seem to have a great relationship."

Shigen shook his head, his tone tinged with melancholy.

Perhaps he couldn't fully understand Tobirama's motivations, having witnessed the brotherly conflict of Asura and Indra during his time.

He sighed and warned Tobirama:

"If you don't remove the curse mark, your movements might…"

"No need to worry."

Tobirama raised his arm, showing how the curse mark's energy flowed through his body like water.

It didn't hinder him at all.

At this rate…

I'll fully master the curse mark by the end of the day, Tobirama thought confidently.

"I've already grasped the core principles."

Tobirama glanced at his brother on the hospital bed and quickly shifted the topic.

"Let's place the curse mark on my brother. He has mastered Sage Mode, so he might absorb it more effectively."

"I've been worried about that."

Shigen sighed, extending a hand toward Hashirama's arm.

A dark curse mark appeared and vanished just as quickly.

As expected…

The natural energy in the mark was immediately absorbed by Hashirama's body.

Hashirama's body naturally converted the curse energy into Sage chakra, causing him to unconsciously enter Sage Mode.

On the bed, Hashirama's face twitched.

His expression grew pained, and he muttered his first words since falling unconscious.

"Madara…"

"…"

Tobirama's face darkened immediately.

Seriously?

Of all the things to say, you're still muttering Madara's name?!

Even in a coma, his brother couldn't stop thinking about that traitorous Uchiha.

That bastard Madara who tried to destroy Konoha with the Nine-Tails…

That bastard Madara who left Hashirama with injuries that shortened his lifespan…

And yet, even now…

He's still worried about that bastard?!

"He should wake up soon," Shigen said softly, breaking the tense silence.

"Although my curse mark didn't work as intended, his body has automatically absorbed the natural energy to enter Sage Mode. His healing will improve, but it might also worsen his lifespan loss if he keeps using that chakra."

"However…"

"As long as he doesn't use his chakra recklessly after waking up, his self-healing won't cause further damage."

Shigen sighed again.

"As for the lifespan he's already lost, I'll need to find a way to fix that. In my time, I relied heavily on Yang Release to heal patients. My medical techniques have fallen behind without it."

"Thank you."

The tension in Tobirama's eyes finally eased.

It worked.

Emiya Shigen had saved his brother.

Tobirama's thoughts drifted to the battlefield where he had carried Hashirama back from his fight with Madara.

At that time, Konoha's best medical ninjas had been completely helpless.

Tobirama's heart was filled with gratitude.

Shigen had not only saved Hashirama but had also been unbothered by being summoned back from the dead and even offered to help repair his brother's damaged lifespan.

"I'm truly grateful."

Tobirama bowed slightly, his tone sincere.

"Without you, Lord Emiya, the world wouldn't have medical ninjas willing to save lives."

But before Shigen could respond with modesty, Tobirama's real motives slipped out.

"My brother's life is tied to the peace of Konoha. His survival holds the hopes of everyone in this village. We'll be counting on you for a long time."

That was Tobirama's selfish wish.

He had no intention of ending Edo Tensei anytime soon.

After all…

He had already gained valuable knowledge about the ancient era from Shigen.

He had even obtained a curse mark infused with natural energy.

Emiya Shigen was a treasure trove of knowledge.

If Shigen hadn't been able to help with Hashirama's injuries, Tobirama would have been forced to let him return to the afterlife. But now, Shigen's selfless devotion to helping Hashirama made Tobirama feel like they were a perfect match.

Shigen thought so too.

Of course, Shigen had to maintain his image as a benevolent medical ninja, so he glanced at Hashirama and gently reminded Tobirama:

"He's about to wake up."

As Shigen predicted, Hashirama's eyebrows twitched, and the Sage markings on his face faded.

The First Hokage suddenly sat bolt upright in bed, as if waking from a terrible nightmare.

He gasped for breath and, with fear in his voice, shouted the name of his closest friend and greatest enemy.

"Madara!"