Kasek: Here's the story behind this one. It all started when I read a (rather bad) Naruto/Ben 10 crossover, and then I was like "Someone needs to write a good one, a really good one." And since I was bored, I started to write one. Don't think I'm gonna finish it, so that's why it's here instead of there. As usual, notes on what the future would've been are at the end.

Disclaimer: I own neither Naruto nor Ben 10.

Omnitrix Ninja

Naruto looked up from his spot leaning against the shack in the woods. He was tired from running there with the scroll on his back, but not tired enough to ignore the large meteor that flew right over his head, its flames illuminating the clearing he was in. He got up and immediately ran towards it when he heard it crash into the ground a distance away, leaving the scroll behind. He soon came to the site of the crash, and he whistled at the long trench the meteor had dug into the ground when it had landed, dirt having been sent flying far from the trench itself, several trees uprooted and knocked over.

He could see the completely spherical object at the end of the trench, steam rising from it at many different spots along its surface. He walked into the trench- it was certainly both deep enough and wide enough to accomodate a full-grown man. He cautiously approached the meteor- as he got close, he could feel its heat, but at the same time, he could feel it cooling down. It kind of looked like a pill bug, all curled up, only it seemed to be made out of metal. It got cool enough for him to approach it, and he stretched his hand towards it. Suddenly, the sphere opened up, the top half of it splitting in two, the many metal plates retracting into the sphere.

Naruto was bathed in a green light, and he shielded his eyes for a moment before lowering his arms and staring at the center of the hollow meteor. Floating inside of it was what looked like to be an arm bracer, with some odd hourglass-like emblem on the top, inside of a raised circle. He reached out towards it, and suddenly... it moved. Not like just moving along a plane, but it turned into a gelatinous mass and oozed towards him through the air faster than he thought something like that could move, and it attached itself to his left arm before he could truly react.

He waved his arm in a panic, obviously not liking the feeling of it on his arm. But already he could feel it seeping into the very core of his being, not just physically but spiritually as well. After a moment it flashed with that green light again, and then the light was gone. Naruto blinked as he stared at the thing that dared attach itself to him. He raised his right hand to it, and started pulling on it. He sighed when it didn't budge- he could feel the skin underneath being pulled when he pulled on the strange item.

He examined it more carefully now that he was apparently stuck with the thing. It looked like it had several dot-like buttons along the emblem, and he decided to see what would happen if he began poking and prodding it. He pushed one of the buttons, and the raised circle raised even further, and the grey shapes on the outside of the hourglass crossed the green hourglass, and the green now looked like a diamond. Inside of the diamond appeared a black image. It kind of looked like a person- it had two arms and two legs, and a single head- but... it was different, somehow. He was about to press another button when a voice called out to him. It sounded quite angry with him. "NA-RU-TO!"

Naruto panicked, and his hands reflexively slammed down on the device, lowering the emblem back into place. Naruto's world turned green, and he could feel himself changing. Like, rocks were growing out of his skin and stuff. After a moment, it was over, and he for a moment he wondered if it had really happened. He turned to where the voice had come from and spoke. He didn't notice, but his voice was significantly deeper. "Uh... hello, Iruka-sensei. What are you doing here?"

--

Iruka was horrified. He saw Naruto flash a bright green, and then he was replaced with... whatever that monstrosity was. It looked like it was composed of red-hot rock plates interlocking together over a yellow substance, with the yellow showing through only in the cracks, although the creature's two hands and two feet were made of the yellow stuff. It had a red, skull-like face, wreathed in flames. On its chest, even though Iruka didn't know what it was, was the same raised hourglass emblem that had been on the bracer. It hid its hands behind its back, looking very nervous- like a child caught with something they shouldn't have their hands on. "Uh... hello, Iruka-sensei. What are you doing here?"

The Academy sensei blinked for a moment. Could it really be...? "Naruto? Is that... you?"

The creature blinked back at him. "Wha? Of course it's me, who else would I be?"

Iruka rubbed his hitai-ite in annoyance. "Oh, I don't know... maybe a fire demon come from the sky trying to impersonate Naruto? And doing a miserable job of it considering it's in its fire demon form right now?"

Said 'fire demon' blinked again, and looked down at itself. It jumped in shock. "What the-?! How the-?! What happened to my body?! And my clothes?! ....and my voice, too!"

The man carefully walked into the trench, and approached 'Naruto'. "Naruto, I want you to tell me exactly what happened. Does it have anything to do with this meteor?"

'Naruto' looked guilty. "Well, uh... I approached the meteor, and it opened up, and there was this bracer inside, and it kinda put itself on my arm, and I started fiddling with it, and when you called out to me I accidentally pushed a button I maybe shouldn't have."

Iruka sighed. "Look, we'll figure out a way to get you back to normal. In the mean time.... why don't you tell me where that scroll you stole from the Hokage's house is, hmm?"

Naruto could feel the anger in Iruka's voice. "Oh! That! Uh, I left it at that shack when I saw the meteor... Come on, I'll show you!"

As they ran towards the shack, Iruka questioned Naruto. "Why in the world did you steal that scroll, Naruto? You know the Hokage won't be able to forgive you for something like that!"

Naruto scratched the back of his head, obviously not bothered by the flames. "Duh! Mizuki-sensei told me about that optional exam!"

The sensei he was with was confused. "What optional exam?"

The boy turned fire demon seemed just as confused. "Uh, the one where I steal the scroll, learn a technique, and I get to pass. What other optional exam is there?"

Iruka's eyes widened in realization. "But... there is no such exam... which means that Mizuki must have used you for his own gain!"

They reached the shack, and Naruto scratched the back of his head again when he didn't see the scroll. "Uhhh.... oopsie daisy?"

There was a rustling in the bushes, and they both turned to find Mizuki walking towards them. Mizuki's curiosity about Naruto was shining in his eyes- either that or it was Naruto's flames reflecting in the darkness. "Iruka? What's with... that?"

Iruka tried his best to be non-chalant about Naruto. "Oh, this is... umm... a being that came down with that meteor. I'm bringing him to the Hokage." Not a total lie. "You have any news on Naruto yet?"

The other sensei nodded. "Yeah, they caught him, and both him and the scroll are being sent back to the Hokage."

Iruka nodded. Best to play along. "Alright, then. I guess we should get going." Mizuki turned his back, and in that instant Iruka made his move- he took out a large amount of ninja wire, and proceeded to make many loops. In another instant the loops were around Mizuki, and Iruka pulled on the string, tightening it around his 'partner'. Mizuki's eyes were wide with fear as he fell to the ground, his knees having been pulled out from under him.

"What the- what in the names of the four Hokages do you think you're doing?"

The scarred chunin grunted as pulled on the wire again. "I'm no fool, Mizuki. Naruto told me how you set him up. Now where'd you put the scroll, he left it here earlier."

Mizuki looked at his partner as if he were crazy. "What are you talking about?"

There was a beeping sound that repeated itself over and over, and Naruto realized the emblem on his chest was flashing. The beeping got lower and lower, and in a flash of green light he was back to normal. He mentally cheered, and took advantage of the situation. "Well, for one, how could I be captured if I'm right here?"

The silver-haired man's eyes were wide with horror when he realized the implications of what was happening. "I... but he... but I..."

Iruka merely sighed. "Now, the scroll, if you please?"

Mizuki's eyes focused on Naruto. "It's in the bushes... why don't you send the demon boy to go get it?"

It was Iruka's turn to have his eyes widen with horror. "You..."

The blond boy merely shrugged it off. "So I'm a demon now, eh? Well, that's what I get for messing with that meteor..." He walked towards the bushes, leaving Mizuki with a big scowl on his face- whatever he had intended, it didn't work. Naruto came back a minute later, scroll in hand. "Got it, Iruka-sensei!"

Iruka smiled. "Good. Now to bring these back to the Hokage..."

They were about to leave when the shack behind them exploded with force, and they all whirled around. Standing in the wreckage was a large... well, Naruto could only describe it as a thing. It was big, taller than the shack had been, twice as tall in fact. Whatever it was, it was covered in red armor. It had three legs to stand on, though they certainly weren't human legs, more like those of a spider. It had a human-ish body, with two skinny arms that had very large hands. It's head was bizarrely-shaped- it was elongated on the z-axis, the head itself curved. It had two large orange eyes, that seemed like an insect's eyes.

Naruto panicked, for obvious reasons. "What in the world is that?!?!"

Iruka knew it had come from the sky, just as the meteor had. "I don't think it's of this world, Naruto... it must have come here for that meteor."

Naruto waved his left arm, apparently emphasizing the device on it. "Okay, I get it, I shouldn't have touched it!"

The thing stared at him for a moment, before rushing towards him and attempting to grab him. Iruka grabbed the boy instead and jumped away, leaving Mizuki behind. He dropped Naruto back on the ground a distance away as the thing paused and turned its head to look at them, and reached into the shuriken holder on his leg, bringing out several shuriken. He threw them, trying to aim for the thinner parts on the arms. The monstrosity didn't even bother trying to shield itself, all of the shuriken bounching off.

The thing raised its left arm, and Naruto could see a circle on its palm. The circle glowed brightly, and a beam of light shot out from it and hit Iruka straight in the chest. Naruto's eyes were wide with panic. "Iruka-sensei!"

Iruka groaned as he got back up again, and looked down at himself- his vest had been burned through, and the shirt underneath was singed as well. "Note to self- run when it does that."

Naruto grit his teeth. What could he do to help fight this thing? If only he were still that fire demon... He looked down at the device on his arm. The emblem was red instead of green, and when he tried pushing buttons, it didn't respond. Angrily, he looked back up at their opponent. The monstrosity walked forward and leaned over, attempting to grab Naruto again. Suddenly, Iruka shot past Naruto and jumped on its arm, and began running up towards the neck, kunai in hand. It tried to swipe him off with its other arm, but he jumped over that and landed in front of the head, and hacked at what appeared to be piping that connected the head to the inside of the body. Iruka managed to make a cut into it, but he received a nasty shock, and with a yell he was knocked off with the thing's arm and he landed next to Naruto.

Naruto kneeled next to his sensei. "Iruka-sensei!"

Iruka coughed- he thought he had heard a bone or two snap when he was hit, if not when he landed. "Naruto... get out of here..."

The blond shook his head. "And leave you here? I may not be a ninja, but I'm not going to abandon a comrade!"

Iruka coughed again, and smiled. "You idiot... this thing's after you... I care too much about you to let it take you away... now go! It might not be able to keep up with you in this forest!"

Naruto could feel tears welling up in his eyes. "Iruka-sensei..." He wiped them away, and with a nod he ran into the forest, hoping to get as far away as possible. The thing began following him, but Iruka managed to get in front of it, kunai poised to strike, face set in determination.

"I won't let you take him!"

--

Naruto heard the explosion, and stopped and turned around, though he couldn't see through all of the trees. "Iruka-sensei!"

Someone landed on a tree branch behind him. "Found you, you little brat..."

He turned, and saw that it was a grey-haired jonin, with his hitai-ite covering his left eye and a mask covering the lower half of his face. Naruto realized that this man could help. "Please! You've got to help him, he's in trouble!"

The man raised an eyebrow. "Who's in trouble now?"

Naruto shook his head. "Iruka-sensei! It was after me, but he held it off while telling me to run... and... he... that explosion..."

The grey-haired jonin could tell he was being sincere. "Come on, then... show me where they are."

--

Iruka coughed with his back against a tree, and some blood dribbled down his chin. He didn't look down- he did not want to know what state his chest was in after that attack. Whatever the case, he couldn't fight anymore- it was too painful to even move. He could see the thing charging up another light beam. Naruto...

"RAIKIRI!" A flash of lightning, and the thing's arm fell off, and Iruka could see a grey-haired jonin standing in front of him. "Just great... looks like one of Vilgax's..."

The brown-haired chunin was confused. What kind of name was Vilgax? "....huh?"

The man chuckled. "Ah, sorry, talking to myself... I'll clean up here." His hand crackled with electricity, and then he charged at the thing. He jumped onto the chest and clung to it for a moment before thrusting his hand into the center of its chest. The thing froze, and then slumped over before falling down, the man jumping off before he was crushed.

Said man turned to face Iruka. "Geez... not really wise for a chunin to go against an enemy of that magnitude. Though... if you did it for Naruto, then I admire your dedication to your students."

Iruka coughed again. "I won't let anything lay a hand on my students. It's my job."

Naruto came out of the bushes now that the trouble was over. "Iruka-sensei!" Iruka could see the boy's eyes welling up with tears when he saw the condition that his sensei was in. The other man put a gloved hand on the boy's shoulder.

"Come on, we need to alert the medical squad... and get you..." and then he pointed at Mizuki, who was halfway out of the ninja wire. "...and you to the Hokage." Mizuki cursed his luck- he had almost escaped, too!

--

The Hokage- Sarutobi Hiruzen- sighed. He had already dealt with the traitor, and now it was time to deal with the boy. The boy hadn't knowingly done anything wrong, so he was off the hook in regards to his 'crime'. However, the device from the stars was a different matter. "Naruto, what can you tell me about that device?"

Naruto gulped nervously. "Well... it came from the sky, and... umm. When I messed with it, it turned me into this fire demon. The transformation had a time limit, and it was a little while after the transformation was undone before the thing allowed itself to be messed with again."

The old shinobi exhaled, some smoke rising from his pipe. "Naruto... what I'm about to tell you is considered an S-class secret. That... device... if it is what I think it is, then... it is one of the most powerful artifacts in the universe. The Omnitrix."

The younger boy tilted his head. "The... Omnitrix? Whuzzat?"

Hiruzen sighed again. "The Omnitrix was made by an alien named Azimuth. It..."

Naruto's eyes widened in shock. "An a-a-alien?! Like, from outer space?!"

The wizened Hokage nodded. "At any rate, Azimuth made this device, as a means to promote understanding. It can turn the wearer into just about any intelligent creature in the known universe. It is meant to make the wearer 'walk a mile in another's shoes', if you will. However, there is just one problem with this- many creatures have unique abilities, making the device very desirable as a weapon. You were attacked by a... machine, that we are fairly sure belongs to an alien named Vilgax. A terrible creature, him... we're going to need all of the help we can get to keep the Omnitrix away from him."

The blond gulped again. "So, what do I do? I mean, how do I fight that kind of thing if he comes after me?"

Hiruzen gained a little twinkle in his eyes. "Well, now... that is a dilemma. I think I have an idea, though- I'll make you a shinobi."

Naruto's breath hitched. "Wh-what?"

The old man nodded again. "Yes... you see, I decided to take a close look at the Academy recently... I discovered that there were many times when people refused you aid when you needed it, even though they already had or were going to aid another student with the same thing. Not only that, but when they did 'help' you, they purposefully taught you the wrong thing. I believe that should you be given proper training then you could blossom."

For the third time that night Naruto had tears in his eyes. "O-old man... thanks... a lot."

Old man Sarutobi nodded. "You're welcome... Naruto. I'll have a hitai-ite ready for you tomorrow."

Naruto nodded. "Y-yeah. I won't let you down! I'll become a great shinobi! I promise! And I never go back on my word!"

--

As Naruto left, Hiruzen sighed yet again and looked at a set of pictures on the wall- they were of the four Hokage, himself included. He stared into the eyes of the fourth one, a blond man with spiky hair and blue irises. "Minato... looks like your child has gotten caught up in the same war you yourself participated in... I can only hope he's ready for the responsibility."

--

Kasek: Notes time!

Naruto didn't learn Shadow Clones for obvious reasons if you're a Ben 10 fan. For those who are not- let's just say that more than one Omnitrix is a really bad idea.

Sasuke would be the Kevin equivalent in this story. His mother was an alien his father came across during his time as a Plumber-equivalent (don't know if the Plumbers originated on Earth or not, need to check that). He's able to absorb all of the things Kevin can, plus chakra. Dunno if he should still have Sharingan. When he betrays the village he tries to absorb the Omnitrix with predictable results.

I suppose Sakura would be the Gwen equivalent. She wouldn't get magic, just the mana powers, which Jiraiya will be able to sense and then be able to train her to be a sage at a later point in the story.

Orochimaru will have never been human- he's a parasitic snake-like alien, who takes over humans and then adjusts their appearance to suit his needs. Naruto would eventually absorb his DNA into the Omnitrix, and then since Orochimaru's DNA works like Ghostfreak's, Naruto would then have a voice in the back of his head who is not Kyuubi. He would then train Naruto so that he would have a suitable body to take over when the time came.

I suppose that with Sakura training under Jiraiya and Naruto under Orochimaru, Sasuke should train under Tsunade XP Kidding.

For the heck of it, there'd be a villain named Aburame Afure, who would be the Naruto world's Clancy. I don't know how'd he'd fit, maybe filler or something.

Orochimaru and Kabuto would get their hands on alien technology and make machines similar to Dr. Animo's. Just for the heck of furthering the crossover. Also, the Sound Three would have access to higher tech, like Zaku would shoot lasers from his palms or something.

And who knows how Vilgax would fit in here... Mebbe he'd attack during the Chunin Exams.

I kind of want Minato to have died in an epic battle with Vilgax, but that would make Vilgax stronger than the Yondaime. So yeah, not gonna happen. I'll just say that Vilgax was defeated by Minato in the past. When he finds out what Naruto looks like, he will not be pleased.

The Omnitrix was meant to go to Minato, but it's kind of been a long time since anyone's communicated with the ninja world.