Here's another one-shot that I'm helping Dragon Sage God with again, if anyone is interested in adopting please inform me.

A Devil's Monkey

Chapter 1

Pilot

The Valley Of The End

As the name implies, The Valley Of The End was the place where The first Hokage, Hashirama Senju and Madara Uchiha had their final battle, where one wanted to take the title of Hokage while the other was given the title by the people of Konoha.

Yet it seems, time has now repeated itself, only instead of fighting over the title of leader, it was two 13 year old boys, one being a black haired, black eyed boy, wearing a blue shirt with a white and red fan on his back, along with white shorts, wanting to leave his village in order to gain power for revenge, using a corrupted seal given to him by one of Konoha's greatest traitors, Orochimaru, at the moment, the boy's skin was grey, he had clawed fingernails, a star-mark above his eyebrows and hand-like wings growing out of his back.

While the other boy was a spiky blond haired, blue eyed boy with whisker-marks, wearing orange trousers and an orange and blue jacket, wanting to bring the other back to his village, wanting to keep a promise to his other teammate.

At the moment, a red fox-shaped aura was covering the blond, along with red slitted eyes, claws and fangs, giving him a feral look.

These two 13 year old boys were Sasuke Uchiha and Naruto Uzumaki, respectively, and they were pretty worn out.

Both had fought long and hard against each other, Naruto's left arm was numb, he couldn't even move it, though he only has enough strength for one more attack, bringing his right hand up and focusing his chakra into the centre to form a spinning ball of blue chakra, which became purple because of the fox's chakra.

Sasuke's body still wasn't use to the stage 2 curse-mark, he was giving it his all just to keep it together, his human hands went through the handsigns for his final attack as well, holding his left hand with his right, having lightning chakra appear, which slowly turned black in colour, showing the corruption of the curse-seal

Suddenly both boys leapt at each other, meeting in the middle of the waterfall with a yell of their attacks.

"CHIDORI!"

"RASENGUN!"

As soon as the attacks met in the middle, a blinding flash covered them, no-one could see what was happening, until the flash died down, turning into a giant black orb.

Suddenly, an object was thrown out of the orb, hitting against the wall of the valley, making a dent with spider-web cracks, in the dent was Sasuke Uchiha, knocked out and pinned to the wall.

Unfortunately, Naruto was still in the orb, before anything else could happen, the orb suddenly vanished into nothingness, along with Naruto inside it, disappearing without a trace.

In Between Worlds

While floating, Naruto was unconscious, in both mind and body, meaning, he couldn't speak to the fox, the fox on the other hand had a different idea.

Mindscape

The fox wasn't sure what to feel about what happened, it didn't know if it should be angry at being inside someone who ended up in between worlds, since they're no longer in their home world, though on the other hand, the fox didn't have to worry about anyone trying to seal it up anymore for it's power, though the problem was the unexpected trip, the fox could "feel" Naruto's body being torn apart, extremely slowly, hence why Naruto was completely knocked out, if they stay in this place any longer they'll ceases to exist, just become nothing.

So with that in mind, the fox "looked" around, "Come on, there has to be something that can stop this brat from dying!" Luckily the seal allowed the fox to sense if the host was in possible danger, health-wise, allowing Kyuubi to send enough chakra to heal Naruto, but because of the urgency of the matter, Kyuubi can use the seal for this reason, now that even it's life was in danger as well.

The fox kept on searching, looking deeper into Naruto's DNA, "The Uzumaki genes can only help so far, they can't keep up with this sort of healing, maybe if I look even deeper, before the Uzumaki's progeny must have something!"

He searched a little deeper, until he came across something that might help it, and Naruto, "Hmm!? Wait, this strand isn't human, it's not even of the Otsutsuki Clan," Suddenly the room began to shake, "Bah! I don't have time to study it, I'm going to have to enhance it with my chakra to such a degree that Naruto's entire body will be changed forever, after this I'll be too tired to study the changes, hopefully I can recharge in the new world."

So with the fox's life on the line, and Naruto's too, Kyuubi focused as much chakra as he could into the gene, causing a sudden backlash of energy to explode in the mindscape, and because of that energy in threw the kyuubi into the back wall of it's cell, knocking it out due to how much chakra it used, along with the collision against the wall.

Before it blacked out, all it could think was, "H-How can a gene have such amazing power...!?" Then everything went black for Kyuubi, the last thing it saw was a silhouette of a tall muscular figure, his arms crossed, with palm tree-like hair and his outfit blowing in the wind from the explosion, with a white circle on his back with the kanji for Go in the middle of it.

Outside.

During this alteration, Naruto's body exploded with energy, allowing an opening to appear, spitting the boy out, though not looking the same as he went in.

Instead of his natural blond hair, it was now completely black and slightly longer, breaching out on the left side of his face slightly. (A.N. Teen Goku's hair style.)

His clothes were now ruined, all that's left were his burnt "shorts," since the bottom half was now black with bunt edges, along with his headband though the metal was the only thing to survive.

Another thing that was different about him was his muscles, instead of being malnourished due to eating mostly ramen, he was now packing a much more stronger build. (A.N. Again Teen Gohan build.)

He still kept his whisker-marks, but you couldn't really see them because Naruto was unconscious facing the ground.

But there was another glaring difference to what he use to look like as well, just below his lower back was a brown furred monkey tail, due to being unconscious the tail wasn't moving.

2 Hours Later.

Slowly, his hand began twitching, his eyes flickering and scrunching, he could feel his eyelids against the ground, so, slowly scrapping one hand above his head, then the other, Naruto slowly pushed himself up, though he was still aching from the travel, as well as the changes to his body, but he didn't know that.

His vision was blurry, moving his head from left to right, trying to focus his vision, everything began to clear up, he can now see that he's in a forest somewhere, but he doesn't know where.

As he was looking around, the sun was reflecting off of something, looking down, he spotted his headband, or at least, the metal part of it.

Picking it up, Naruto puts it in his pocket, being thankful that his pockets weren't damaged along with his shinobi sandals, though the moment he looked at his body, he was shocked, he couldn't believe the muscles he was now packing, "D-Did I always had these muscles!?"

He began poking and prodding his muscles, not believing his eyes at how strong they felt, rubbing his hand over his head, he suddenly felt his hair was longer, quickly looking around, he spotted a puddle near by, rushing to it, he couldn't believe his eyes, he still had his blue eyes and whiskers, but now, instead of bright blond hair, he was staring at black hair, in a different style.

Rubbing his head in shock, along with his more stronger, leaner looking face, gaping in surprise, "WHAT THE HELL HAPPENED TO ME!?"

Suddenly, he felt something twitch behind him, turning his head slowly, there, before his vision, was a brown furred monkey tail, before anything else his vision began to swim, he began to feel lightheaded, his body swaying from side to side, until he ended up collapsing over the puddle, not caring about the water.

An Hour Later

It took a while for Naruto to wake up, as well as getting over the shock of having a tail, he began making his way towards, hopefully, civilisation to get help.

As he was walking, getting use to his tail by making it wrap around his waist like a fuzzy belt, he noticed two 13 or 14 year old girls, both having a spar with each other, figuring they might be able to help him, Naruto called out to them, "OI, Excuse me, do you know where I am!?" Gaining the girls attention.

Since Naruto wasn't exactly smart, he didn't see the harm in asking the girls, though it seems his luck was on his side for this occasion.

Both girls stopped what they were doing and looked at the person who called, "Oh, hello, I didn't know there was another Japanese here, do you need help!?"

At first Naruto was confused, he didn't think that they'd be so helpful to a stranger, rubbing his head nervously, "Um, yeah, I have no idea where I am, do you think you can help me out!?"

The two girls agreed to help him out, saying how it was god's will to help those in need, or something like that, which kinda confused Naruto, which was easy all things considered.

As the three walked, they introduced each other, with the two girls introducing themselves as Inari and Xenovia, which Naruto was happy to meet a couple of new friends.

As they were walking, they came up to a tall building, making Naruto's eyes widen, as they were about to enter, Naruto suddenly stopped, making the girls look at him in curiosity.

For some reason, Naruto "felt" this dark inside the building, almost like it was coming from something or someone, making him nervous and afraid since the last time he felt something like that was when facing Orochimaru, as it turned out, due to the fox's chakra still in his system he was able to sense the negativity in others, but it was slowly vanishing, since it wasn't enough to stay with him.

Because of this Naruto's energy spiked, causing him to suddenly flicker out of sight, causing the two girls to scream his name and try to find him, as it turns out, due to his loss of control of his energy, he unconsciously used his KI to travel somewhere else, along with that spike awakened someone inside him, but this time, it wasn't the fox.

Two Years Later

It's been two years since he "escaped" from the negative energy, during that time Naruto did the only thing he could, train and study, thanks to the person in his mind waking up, Naruto was now a master of his energy, well, the KI aspect of it, his chakra control still wasn't perfect, so for the time being he trained his KI, all thanks to the man in his head called Goku.

But as it turned out, Naruto was slowly getting weaker, when he first arrived he had his strength, but slowly it was fading, making him just as strong as an above average human, as it turned out, Goku explained to Naruto that he wasn't human anymore, but a full-blooded saiyan, turns out his hidden gene was super concentrated that the sudden burst from the fox's chakra helped with it.

Anyway, it turns out, that because of how he "arrived" in this new world Naruto has somehow ended up with a heart virus, a strong one at that since not even Naruto's healing can fight it.

As he was now wearing a Kuoh uniform along with a new haircut, while his hairstyle was short, it had a couple of bangs. (A.N. High School Gohan hairstyle, with Vegito's bangs.)

Also it turned out, he was still packing his muscles, but due to the virus, it felt like his KI was flowing at a snail's pace, making it difficult to fully use his KI, thanks to Goku pointing out that if he stops using his energy the virus won't spread as fast, but Naruto wanted to be able to master his KI.

Thankfully, during the training, Goku taught Naruto how to build his own home, just inside the forest close to the school, since Naruto wanted to be close to nature.

It was almost like the virus was blocking his KI from him.

During his stay, he realised that he also needs to find out more about the world he was in, meaning he had to go to school, though he doesn't like the thought of it he'll endure.

Now he somehow entered a recently turned co-ed school, due to his looks, Naruto had quite a few girls blushing at how strong he looked, along with how smart he is as well, since he had to learn this world, his old friends would be shocked at how smart he became.

As he was walking, Naruto noticed a young girl wearing a different uniform standing just outside the gates, figuring the best thing to was to try and help, "Excuse me, but is there something wrong, you don't seem to go to our school!?"

Gaining the young girl's attention, her face lit up red at the fact such a muscular teen was talking to her, "S-S-Sorry, my name is Yuuma, I-I-I'm waiting for my boyfriend Issei-kun to pass by so I could say good morning to him." The young girl stuttered, "Wait, did I stutter for real at the last part!?"

Naruto looked at her in honest shock, "WAIT, YOU AND THAT BOOB-OBSESSED PERV ARE DATING!?" Even Goku was shocked, and he had someone like Master Roshi training.

Yuuma's face was bright red at how Naruto yelled such a thing out, causing the girls around the two to start gossiping at such a fact, since nobody thought that Issei, of all people, would end up dating someone, due to the gossiping, Yuuma was actually really embarrassed that someone yelled that.

Covering her face in such a way, she thought to herself, "I can't believe someone would actually yell like that, though given the boy's history, I shouldn't be this embarrassed, but to be seen as a pervert's girlfriend is truly embarrassing!" Turns out, even though she's acting, to hear someone say it out loud didn't help the matter.

Feeling as though he put the girl on the spot, Naruto rub the back of his head in nervousness, "H-Hey, look, I'm truly sorry about yelling out like that, it was just a shock that someone likes that perv, and that he's dating before me." Though considering the virus infecting him, he doesn't want to put a girl through such heartbreak.

Yuuma was still slightly embarrassed, but it wasn't as bad as before, since from what she can sense the boy in front of her was truly honest in his apology, which was a surprise at this day and age.

While they began chatting, with Naruto telling her about his pranks on the pervert and his friends, she couldn't help but find Naruto to be enjoyable to hang out with, especially all the embarrassing pranks he's pulled.

Before anything else, Naruto noticed his victim was a short distance away, huffing and puffing at having to run to school before he was late, "Well I best get to class before I'm late, good luck with the perv."

Hearing Naruto call Issei such a thing caused Yuuma to giggle, during which, Issei was standing in front of her, "S-Sorry I'm (huff) late, my alarm didn't go off!?"

What caused him to finish in a question was the fact that Yuuma was now laughing everytime she looked at him, "What!?" She continued, remembering what Naruto told her, "What's so funny!?" That didn't stop her, "Stop it~!" Turns out it's gonna be a while before she calms down and tells him. (A.N. To get the idea, look up on youtube "Rose and Sarah Jane talk about The Doctor".)

End Of The Day

After school, Naruto began making his way towards the forest by cutting through the park quicker, though, during his walk, Naruto saw an interesting sight, Issei and Yuuma were talking to each other, this made Naruto curious at such a sight, especially when there was a flash of light, blinding both Naruto and Issei.

In yuuma's place was a slightly older looking Yuuma, wearing a strange S&M type of outfit with black wings, making Naruto wonder if she was a magician or something.

Though before anything else, Yuuma held her hand out, creating a pink light spear thing out of thin air, aiming it towards Issei, he didn't quite hear what she said, since just as he got between the spear and Issei, the thing pierced his heart, causing the perv and the fallen to stare in shock at such a thing to happen.

Yet all Naruto could think of was, "If only the virus wasn't infecting my chakra and heart I could've done more than this."

Due to the shock, the light spear vanished, causing Naruto to fall on the floor, blood coming out of the wound and his mouth, Issei was yelling at him, though he couldn't hear him, the winged girl looked shocked at the sight, until she was knocked out of her shock and threw another light spear at the Issei, causing the boy to be thrown and stabbed into the pavement.

Naruto couldn't help but think, he could've done better, but because of this stupid virus, he couldn't save someone, not even himself.

He could see Yuuma slightly, just as his eyes were getting heavy, Naruto swore he saw a tear leaving the girls cheek, though whether that tear was for him or for Issei, Naruto had no idea, the last thing he saw of the girl was some black feathers fluttering everywhere, then his eyes closed to darkness.

With both boys not realising the type of adventure that awaits them, all thanks to the pervert having a certain piece of paper in his pocket.

The End.

There you have it, a Saiyan-Naruto in Highschool DXD world, also due to Naruto's travel through the Dimensional Gap he has a virus that blocks his chakra and is slowly killing him, that is until Rias saves him by giving him her Rook piece, allowing him to regain his blocked energy, making him as strong as he should be, but due to the power Naruto isn't a half-devil, but somehow gains a devil's magic and longevity.

Also as for pairing(s) I figure it best for whoever adopts to work it out with Dragon Sage God, since it is his idea that I'm helping him with.

I Do Not Own Naruto Or Highschool DXD. (Or Dragon Ball.)