The Rinne Tensei was Nagato's ultimate technique, the culmination of the Rinnegan's power.
The Seventh Hokage remembered that day with perfect clarity. Nagato had summoned the King of Hell itself, a massive spectral entity rising from the earth like a mountain given form. Its mouth had opened, and from that void poured forth countless souls. Translucent spirits returning to cold bodies, life flooding back into the dead. Everyone who had fallen during the Akatsuki Raid, resurrected in a single magnificent act.
But the price had been absolute. Nagato's life, consumed completely by the technique's demands.
When the Seventh Hokage first heard that young Naruto wanted the Rinne Tensei to resurrect his parents, his parents in that other world, his instinct had been to refuse. The technique was too dangerous. Too final.
But then he'd considered the boy standing before him. This Naruto's strength transcended anything he understood. The kid had crushed him in combat without even trying, had transformed into a two-hundred-meter giant, had spoken casually about achieving immortality as though it were merely a matter of time and effort.
Maybe, the Seventh Hokage had thought, just maybe he has a way around the technique's fatal flaw. Maybe he'll surprise me.
He'd certainly wanted to use the Rinne Tensei himself, years ago. The desire to bring back his parents had burned in his chest every time he'd held the scroll. But Nagato had died to perform it. Using someone else's life as currency for his parents' resurrection violated everything Naruto stood for.
The same logic applied to the Impure World Reincarnation. That technique desecrated the dead, used innocent people as sacrifices to bind departed souls into reanimated bodies. If Minato Namikaze knew his son had killed innocents to resurrect him, he would never forgive Naruto. The very thought made the Seventh Hokage sick.
Young Naruto shared that same principle, even if their paths had diverged dramatically. For all his casual violence toward those who'd wronged him, the kid didn't ignore life's value. His execution of Hiruzen's faction had been revenge, deliberate and targeted. But random murder? Senseless killing? That wasn't in his nature.
Look at how he'd handled Zabuza, Haku, even Orochimaru. He could have killed them all. Instead, he'd resolved their conflicts, turned them into friends, given them employment and purpose. Transformed enemies into allies.
Young Naruto looked up from the scroll, his expression thoughtful. He'd absorbed every detail of the technique, memorized the hand seals, understood the chakra flow patterns. And he'd identified the two critical flaws immediately.
First, the caster needed the Rinnegan. That was manageable. Sasuke's Sharingan could evolve to the Rinnegan under the right conditions.
Second, the caster died. That was the dealbreaker. Naruto wouldn't sacrifice himself, and he absolutely wouldn't let Sasuke die for this.
But the technique wasn't useless. Every jutsu had weaknesses, and weaknesses could be exploited or circumvented. The Rinne Tensei worked by retrieving souls from the King of Hell's domain and returning them to the world of the living. The root problem lay with the King of Hell itself, the entity that demanded a life for lives restored.
Can't solve the problem? Solve the King of Hell.
It was the kind of direct, violent solution that appealed to Naruto's sensibilities. But he decided to consult the System first. Maybe it had a better approach.
[System,] Naruto thought, reaching inward to that familiar presence. [I've analyzed the Rinne Tensei. Do you think I could modify it to avoid the caster's death? Use it to resurrect my parents?]
The System had been observing through his eyes the entire time, studying the technique alongside him. Its response came immediately.
[Young Naruto, do you understand why I instructed you to resurrect your parents only after achieving eternity?]
[Why?] The question had nagged at him for months.
[Because when you step into eternity, you will be able to forge immortal bodies for your parents. At that point, they will share your eternal foundation. You will be together forever.] The System's tone carried unusual weight. [Otherwise, what happens? Your lifespan becomes eternal while your parents have perhaps a hundred years remaining. Would you not feel that loss keenly?]
The logic hit Naruto hard. He'd been so focused on resurrection that he hadn't considered the aftermath. What good was bringing his parents back if they'd age and die while he remained unchanged? But the same concern applied to everyone he cared about. His wife, his children, all his friends...
The System anticipated his thoughts. [Do not worry. After you transcend the ninja world and explore the myriad realms beyond, you will find heavenly treasures and longevity methods. Your family can walk the path of extended life alongside you.]
[But longevity isn't the same as eternity?]
[Correct. Longevity means a lifespan matching the heavens themselves, vast beyond mortal comprehension. But eternity transcends even that. Eternal beings exist beyond universal constraints, untouched by the cycles of creation and destruction. When heaven and earth perish, the eternal endures. That is the difference.]
Naruto absorbed this distinction carefully. Longevity versus eternity. The gap between them was profound.
[System, you must have longevity methods available. Can you share some? For my friends and family?]
[I possess many such methods,] the System acknowledged. [But your thinking is too convenient.]
Naruto could practically hear the amusement in its voice.
[The Law must not be transmitted lightly. I am responsible for guiding you alone. If you wish to obtain longevity methods for others, you must fight for them yourself. If I simply handed you everything, you would never walk the eternal path. The eternal road requires struggle, conflict with others, with heaven itself, with your own limitations. Only through that tempering can you sharpen yourself into something truly transcendent.]
Well. Naruto couldn't argue with that logic, frustrating as it was.
He returned his attention to the scroll, committing every detail of the Rinne Tensei to memory. The hand seals, the chakra pathways, the spiritual connection to the King of Hell, all of it burning into his mind with perfect clarity.
When he finished, he rolled up the scroll and offered it back to the Seventh Hokage. "I've memorized it completely. You can have this back."
"Keep it," the older Naruto said, waving off the gesture. "I have copies of everything important stored away. If you actually succeed where others have failed..." He trailed off, then smiled faintly. "Mom and Dad would be proud of you."
"I know." Naruto returned the smile, then secured the scroll in his storage space anyway. Having the physical reference couldn't hurt.
"I should go. Himawari's still waiting for me."
Before the Seventh Hokage could respond, Naruto's form blurred and vanished, the Instantaneous Movement technique carrying him across Konoha in the space between heartbeats.
Home felt warm compared to the Hokage Tower's sterile atmosphere. Naruto had barely gotten the door open before a small blur crashed into his legs.
"Young Dad! You took forever!" Himawari's arms wrapped around his knees, her face tilted up with an exaggerated pout that would have melted steel.
Naruto laughed and scooped her up easily. Yeah, he'd been gone longer than intended. An hour "making friends" with Sasuke, another half hour with Sakura, plus travel time and the conversation at the Tower. Over two hours total.
"Sorry, Sunflower." He carried her into the living room and set her down on the tatami mat. "I made two new friends on the way back. Couldn't just leave them waiting."
Himawari's expression shifted immediately from pouty to understanding. She was such a good kid, never demanding or selfish like Boruto could be. But Naruto saw the fear lurking beneath her acceptance. She was scared he'd disappear like her real father always did, scared this magical time with a dad who actually played with her would end.
His chest tightened. This little girl deserved so much better than a workaholic ghost for a parent.
"Hey, Sunflower." He knelt down to her eye level, grinning. "Want to see something amazing?"
Her eyes went wide, all worry forgotten. "Yes! What is it? What is it?"
Naruto concentrated, reaching into the sealed space within himself, and released the cargo he'd been carrying since the battle in the back mountains.
Kurama materialized on the tatami with a soft thump, about the size of a large puppy. Its chakra had recovered slightly during its rest, restoring some of its mass. The fox's eyes snapped open, immediately locked onto Naruto, and its mouth opened.
"Blub-blub-blub!"
Tiny Tailed Beast Balls, no bigger than soap bubbles, shot out in rapid succession. They popped harmlessly against Naruto's chest, barely stronger than blown kisses.
Naruto stared at Kurama. The legendary demon fox, reduced to spitting bubble attacks. How the mighty had fallen.
"WOW!" Himawari's squeal of delight cut through his amusement. "It's a Nine-Tails! A real Nine-Tails fox! He's so CUTE!"
She lunged forward, arms spread wide to hug the creature from behind.
Kurama' expression shifted from defiant to disgusted in an instant. Its hind legs kicked back sharply, catching Himawari in the stomach and sending her tumbling backward onto the mat.
Naruto's hand moved before conscious thought. His fist blurred through the air three times in rapid succession.
THWACK. THWACK. THWACK.
Kurama shrunk with each impact, its form compressing until it was barely larger than a kitten. It lay on the mat, stars spinning around its head.
"Young Dad, don't hit the fox!" Himawari had already scrambled back to her feet, completely unbothered by being kicked. She rushed to Kurama' defense, tugging at Naruto's sleeve. "He didn't mean it!"
"If he doesn't behave, he gets disciplined." Naruto kept his tone firm but not harsh. "That's how it works."
Kurama glared up at him with pure resentment, too dazed to move but still radiating indignation.