Disclaimer: Naruto x Highschool DxD - I own neither
Since fanfiction took down Twin Tails (took me awhile to notice it was down honestly), I'm finally deciding to make a new one.
This time, I've come up with a realistic way for the Cross-Universe Reincarnation to Occur.
Story Start!

"Aaaaaaaah... you know, being dead kind of is amazing, but it KIND of sucks too."

Naruto Uzumaki, died of old age, shouted from the afterlife as he looked around at the paradise around him. He loved it for how great it was, but he hated it because through out his entire life he had done nothing but fix everyone else's problems and lead the world towards peace. He had become the strongest person in existence itself, capable of destroying anything he damn well pleased including the planet if he so choose to do so.

He had been dead for nearly 70,000 years now though.

For anyone else, being in paradise was just a nice blessing and an eternity in paradise was even better. He had his parents, his wife, his children, his grandchildren, and even his great grandchildren in the afterlife with him. He didn't really bond that much with the descendants of his that came AFTER he had died to be honest, but that didn't mean they weren't in the afterlife.

He had no purpose at the moment.

"Idiot, you're literally in paradise right now... and you're complaining?"

"Says the guy that only got here 100 years ago after spending so much time in Hell... it took you awhile to realize you could use your Rinnegan to make a portal between Hell and Heaven." Naruto teased his rival and friend Sasuke.

Sasuke nodded.

It took him remembering that Obito had created a portal using his Sharingan, so that he could teleport himself from the afterlife to the mortal world so that he could possess Kakashi's body and give him the Sharingan again. When they died, they actually got to keep their chakra, and they could still use that chakra in the afterlife. Sasuke had realized that as the small idea struck him that he could leave Hell and go to Heaven, where he could sense Naruto's chakra.

So, he opened a portal and walked right out of Hell.

"So, what are you complaining about... do you want to fight again?" Sasuke offered a way to relieve some of that boredom. Their fights would last for several real world days, and in the afterlife nothing they did would hurt anyone, so they could exert absolutely all of their true power and fear nothing. They couldn't even kill each other, they would instantly come back to... "life" as it were.

They felt no pain, and have infinite stamina, the match just ended when one of them died.

Currently, it was 1,902 to 1,329 in Naruto's favor, since he didn't have to worry about killing Sasuke in their fights the results usually ended in his victory. Still, Sasuke still had his fair share of wins as well when he could use one of his more deadly moves and get Naruto by surprise.

"Nah... that gets a little boring after awhile too... I'm just so BORED!" Naruto landed on his back and complained. He hated being bored and having nothing to do, and he had been bored for literally so long that he sometimes he fell asleep and LITERALLY thousands of years would pass by without him noticing.

What sucks about the afterlife?

You can't learn new skills, you can't get stronger, your body always stays the same, and whenever you DO get a new skill your brains resets itself so that you lose that skill. Naruto was stuck with the prime of his life, and he was stuck with the levels of maturity he had in life. In death, you stopped progressing and weren't able to experience life anymore.

"Bored... well, when Obito and Rin get back from haunting the living world for fun, we can ask them what they usually..." Sasuke paused after a moment when he realized something about their situation.

Obito had a skill that let him and others travel to places he had been before, including teleporting him out of the afterlife to possess others. Thanks to his Sharingan, it was possible for that to happen and the man made use of his skills.

Sasuke had a Rinnegan that could travel between Dimensions he had NOT visited before and those that he had. With his Rinnegan, he could bring people back from the dead, or effect the cycle of reincarnation itself. He could rip souls out of bodies and push them into other bodies if he wanted to.

"Wow... Kind of broken... death is kind of meaningless." Sasuke stated with a bored tone as well. The funny part was that everyone they ever knew, other than those in hell, were currently with them. Not counting Orochimaru who was still alive after all this time, jumping from clone body to clone body. The one person who feared death the most, wasn't around to realize that death was now completely without meaning.

Sasuke could literally just die, travel between the afterlife and life, and just bring himself and others back to life.

Well, he could bring others back to life at least, he didn't know if he could do it with himself.

"I like it here, but after so much time of NOTHING happening... you can't help but feel like you have no purpose." Naruto stated with a sigh of frustration. He absolutely hated the feeling of having no purpose, because he had always lived his life guided by his purpose. "I wish that I have Obito's Sharingan SO BAD right..." Naruto stated, before his eyes shot up.

He sat up instantly.

Sasuke and Naruto made eye contact with each other, and years upon years of being best friends, rivals, and teammates allowed them to have a real good understanding of the way the other thought.

"Ah!/Yes."

They agreed with each other.

"Think our wives will notice?" Sasuke asked with a narrowed brow. They would get into a lot of trouble if their wives noticed that they were not in the afterlife anymore. He didn't want to make Sakura angry. "Wait..."

"No pain, no suffering, and until death do us part. If they are dead, and we are alive, we can escape this boredom for awhile, and then be back before they even notice... and we won't have done anything wrong." Naruto wrapped an arm around Sasuke. Naruto, the GOOD GUY, was the first one to say that he wanted to get out of the afterlife as soon as possible. 10s of thousands of years of piled up boredom would drive any man insane.

Only, Naruto was UNABLE to go insane because the afterlife did NOT let him, so he was stuck in a perpetual state of boredom because of it.

"I know you're bored-"

"Sasuke... not having a purpose, not being able to experience pain, or training, or getting stronger through blood, sweat, and tears... THAT is my hell right there. You were tortured for a long time, but with your pain tolerance that is just a tickle. I want to feel like I've got purpose, and be able to learn new things, and DO new things... this perpetual existence of nothingness... I'm willing to let Hinata and Sakura be angry at us for a couple thousand years even, if it means just 100 years of escaping that." Naruto stated dead seriously.

This wasn't life for him.

This was a never ending, slow and painful death where he felt nothing and could only wait until he stopped thinking completely. Only, he couldn't avoid that because the afterlife didn't even let him abandon all thought and allow him to slip into nothingness.

"I just got here not that long ago-"

"We can be TRUE rivals again... what do you saw Sasuke? You and I have a little competition." Naruto stated.

Sasuke's eyes narrowed.

"I'm listening."

"We go to some other Universe, I pick one of the local races. I find a pregnant lady, and you use the Rinnegan to change things up inside of her. You put my soul into the second baby's body. Then you do the same thing with yourself... and we compete." Naruto stated with a grin. He had Sasuke's attention, as the man had a completely serious face.

He was interested now.

"Compete over what?"

"That is the thing... we'll be alive, we can do whatever we want. We can compete to see who can save the world first, or who can bring peace to the world first, or which of us lives the most impressive life. We die, we come back here, and after a couple thousand years... we rinse and repeat." Naruto stated as he had his fists literally shaking in excitement. This was just the thing that he was waiting for.

Freedom.

"These new bodies won't be able to use our powers, what is to stop me from just picking a genetically superior species... and cheating."

"Do it, that sounds awesome, having a rival stronger than me would be great. Gives me something to surpass. Heck, I'm even willing to wait to start seriously training until like 14 or 15 years old. I want a real challenge, anyway, whatever bodies we get, even if we can't use chakra... we still have our knowledge." Naruto stated, and he just loved every possible challenge that would be waiting for him in life.

He wanted to feel the effort again.
He wanted to be able to sweat and cry as he tried to overcome impossible odds.
He wanted to be able to find new love, and new friends (He would NEVER stop loving Hinata though).

"Are you sure, I could easily just pick a body-"

"Do it Sasuke, in the end, I want to train my ass off and surpass you again. Though, do me a favor and don't be TOO evil?" Naruto asked, since he knew Sasuke still had enough evil in his soul to be able to think up some twisted shit if he wanted to. One did not train under Orochimaru wouldn't having that taint lasting on your very soul. "I want the challenge, I want it. You have NO idea how long I've wanted to feel like my afterlife has purpose." Naruto spoke with certainty.

Sasuke opened a black portal in front of them without another word needing to be said. This was their portal to another dimension, one where they could start new lives as rivals all over again.

Naruto grinned.

"... But wait... question, how will be make sure that our names..."

"Sasuke, Sharingan... just hypnotize the women into wanting to name their children Naruto and Sasuke. You can do that easily, that even if we look a little different, we can still find each other." Naruto cemented Sasuke's willingness to do this.

Sasuke extended his fist to Naruto.

"Together?"

"Hell yeah, together." Naruto bumped fists with Sasuke, and they walked through the portal together on their journey to find new lives to lead.

The never-ending rivalry.

Chapter End!
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