So here's this. I want to say that I want to do Rainstorm over Renmant but its really hard to write and I just don't know where to go with it. I had all these ideas of fights between characters but that's it, only the fights. I got nothing leading up to anything. Maybe I will come back to it, but I doubt it. Me getting info from other fanfics about RWBY is not the best source.

This is why I decided to write a story with things I am familiar with. That being Ben 10 and Undertale. So I can actually write not just fights but other actually important stuff and events. Now, before anyone gets their panties in a twist, this is an OC story. Not Ben. His name is Mars and he has been my OC since Alien Force. Why am I not writing about Ben? Because I don't know how to write Ben. Is Mars stronger or better then Ben, is he a perfect OP self insert? Nope.

So enough of my rabbling, here is Undertale: Mars Edition. Name still being decide but we will stick with that for now.

(Update. I'm sorry for me continuing to switch between ratings. Wasn't sure what to rate this, but I'm gonna put it as Mature and leave it. Better safe then sorry.)

Ben 10 belongs to Man of Action Studios. Undertale belongs to Toby Fox. Any Community created content or characters belong to their original owners.

Undertale: Mars Edition

Chapter 1: Two Fallen Humans

A young child in a blue shirt with pink stripes, rested on their stomach, face to the side in a small field of yellow flowers within a massive cavern. Light shined down on the field for there was a large hole on the roof of the cavern, an exit to the surface.

The child slowly stirred conscious, slowly getting up to a sitting position on the knees while rubbing their head from the small ache. They began to look around survey the area, trying to figure out where they are.

Looking up to see the hole on top of the underground room they guessed they must have fallen down it and luckily landed on this large bed of flowers to break their fall. They shrugged at the thought and slowly got on the feet, still feeling a bit dizzy and not wanting to meet their face with the ground again. Looking around the area again they actually spotted something. Actually it was someone.

They quickly made their way over to the persons side a saw that it was a man laying on his back covered by some broken flowers and petals. The child guess the man had a rougher landing. The child squatted to the mans' side getting a better look at him. He had messy brown hair and 5 o'clock shadow? The child shrugged and looked at the mans' outfit. They wore what looked like a strange black and orange light space suit or armor? Like something out of a sci-fi movie. They also a pair of orange semi rimless gray one lens shades still on their face, not even broken from the fall. If they did fall. Maybe the decided to take a nap here and cover themselves in flowers….The child concluded they probably fell too.

The child then stared, with their partially closed eyes, and mouth slightly open in awe as they notice something about the mans' left arm. It looked like it was made of metal. A bionic arm? Definitely out of a sci-fi movie. From their hand and fingers all the way up to their shoulder was a shiny black arm. Had some stripes of orange too. Seems like orange is this strangers' favorite color or something. Also there was what look like an orange forearm-length cuff or gauntlet with a small display screen on the metal arm.

Wondering what that does they made the child went to the left side of the man to see, but decided to see if the man was even still alive first. The child saw a stick nearby a grabbed it. They then proceeded to poke the stranger in the cheek a few times waiting for a reaction.

No response.

They went to do it again, but froze when the man spoke in a low voice.

"Poke me again and I'll shove that twig up your nose all the way to your brain, kid."

A moment of silence before the kid threw the stick over their shoulder. Not wanting to see if the man was bluffing or not.

The child watched as the man sat up with a groan of discomfort while rubbing their back. "Damn. Laying on flowers are really bad for the back." the man twisted and their back made a popping sound. The child winced at the gross noise.

The man turned their attention to the child. His eyes hidden behind glasses and the childs' hiding their own. Before stared in silence at each other waiting for the other to make the next move.

The man broke the silence. "You shouldn't stare at people." he said "It's rude...and kinda creepy." The child responded by pointing at the man. The older man seemed to know what the kid was implying and frown before he spoke again.

"I'm staring at you cause you're starring at me." the man pointed back. "You little weirdo."

Another staring contest began. This time with both opponents pointing at each other. However the man eventually gave up. They turned away and began to get on their feet. "Whatever." the man added.

The child gave a soft smile and internally cheered at winning the staring and pointing contest while watching the man stand up and brushed the flower petals off of himself. The man noticed the child smiling but decided not to comment on the kids' weird behavior. Only raising an eyebrow to them.

The man shook their head then like the child before looked around the cavern. Looking up at the large hole on the roof the man thought to himself.

'Did I fall from up there? I don't remember falling.' he put a hand up to his chin. He was too deep in thought he didn't notice the child mimicking him. 'Did I hit my head? I don't have any head pain though. Plus Megan could just...Wait' he looked down at the cuffs' display screen on his bionic forearm. 'Megan's out. Gotta wake her up.'

The man started to tap the screen. "Yo, Megan. Rise and shine girl."

No response. The child tilted his head at the man with a raised eyebrow. Confused on why they were tapping the screen and calling out for someone named 'Megan'.

The man tapped the screen again. "Megan! Wake up!" the man was getting frustrated. The child wondered who this Megan person was and if they were just as grumpy as this man.

The man then shouted. "MEGAN! WAKE THE FUCK UP!" the child jumped a little at the sudden increase of volume but also at a screen lighting up and a women shouting back.

+AAAAAAH!+Both his arm and screen in his shades came to life with numbers and words of stats, time and locations. +What the hell, Mars!? Why did you scream at me!?+ a female computerized voice came from his bionic arm screen.

Now know as Mars looked at the arm screen with a smirk. Satisfied that it display a bright orange background with two feminine digital eyes looking back rather...unhappy. "I called you twice to wake up but looks like you were to busy in AI dream land. So I called a bit louder. With an f-bomb added in for good measure." he replied casually.

+Well it was not necessary.+ the computerized eyes "looked" away from Mars with a scowl and huff. Then she noticed the child. Staring at them confused? Kind of hard to tell when they look like their eyes are closed. +Who are they?+

"Hm?" Mars turn to see the child before answering. "Oh, not sure. They were here when they woke me up. By poking me in the face with a stick like a dead animal." Mars gave the child a look but the child just smiled a little and shrugged.

+You don't know their name? Why didn't you ask? Also you should watch your language in front of kids. They are too young for you potty mouth.+ Megan questioned and advised Mars.

Mars rolled his eyes behind his shades at the last statement. "Like I said, I just got up from laying in this flower field. Didn't really think about it. To focused on the back pain, where we are and waking you up."

+Well, we should introduce ourselves then.+ Mars turned to the child to see them with a blank look. Mars returned the expression.

+Hello there, little one! My name is Megan. I am a close partner and friend to this man here.+ Megan introduce herself first. +And yes I am talk from his arm. For I am an AI operating the device connected to his bionic arm.+ Mars lifted his metal arm and flexed his fingers. Then spoke up with a sincere friendly face and warm smile.

"My name is Marley Flix, but I liked to be called Mars. As you heard from her." he gestured to Megan. "We are an elite specialists of the intergalactic law-enforcement organization that protect the innocent and good from villainous threats and attacks known as the Plumbers." Mars gave a wave to the child who returned it but with a bit of confusion on their face. Wondering why there is a police force called plumbers. A bit of a silly name and did he just say intergalactic. Like space police? And they are named plumbers?

The child stopped their thoughts when the man spoke to them again. "So shorty, what's your name?"

There was a long silent pause. It made Mars wonder if this kid was just shy or nervous in front of strangers which makes sense. Or just a mute. Though the child finally spoke.

"M-my name is Frisk...officer, plumber, sir."

That's it. First chapter. Short, yes but I will work on the others more later. More about Mars, you will know more about him and his life story/past throughout the story. I don't want to spend one whole chapter telling about how much Mars likes cats or something. That chapter would be pretty boring and more boring to write. About Mars' "Omnitrix", it isn't. I was gonna call it the "Omegatrix" but there are so many OC omnitrix names like that and someone probably already has that so it will be called something different. Was it is? I don't know yet but when I do you will too.

And I think that's it. I may actually enjoy writing this one. I got plenty of ideas for it. I also am happy with not replacing Frisk. I didn't want that and that has been done to many times before with other stories. Frisk and Mars will be friends and being going through this adventure together.

Thanks for reading. Constructive comments are welcome, but flaming or whatever will be ignored so don't waste my time.