Hello folks! Human Soul here with a new story! YYYOOOOHHHOOOO! First, this crossover is a challenge create by Rexfan1333, I accepted it and here it is! I hope you will like it, and don't forget to check out Rexfan1333, , and the others writers at my favorites lists. If you like this story, you may want to check my other (cause for now I only have two, he he *sweatdrooped*) Anyway here is the key

"hello" = talking

"hello" = thinking

For now you all will only need those two keys and be warned that the key may change throughout the story or for specific chapters, so I highly recommend to read the key of every chapter

Disclaimer: I don't own Ben 10 or TMNT

Now enjoy the chapter

Chapter 1º: First day at New York! The beginning of a new Adventure!

In the city of New York, an alien invasion happened some weeks ago, bringing with it immense destruction to the city and kidnapping many people, but fortunately, it was prevented by some hero, which let the world to believe it was the plumbers who defeated the aliens, above all they thought it was the alien boy hero, Ben Tennyson who saved the day, but surprisingly, it wasn't him or the plumbers, so Ben was send to New York to find out who saved the world this time

He is in for a big surprise…

Inside of a green, spaceship-like plane, there is a teen, he has brown hair and green eyes, no older than seventeen, wearing all-starts, jeans, a black t-shirt, a green jacket with a black line that had a white circle with a black '10' where his heart is located. But his most striking thing in him is a neon green gaulet with a hourglass symbol in its end

It is the alien hero, Ben Tennyson! And he was going to New York in a solo mission to investigate about some strange happening… apart from the alien invasion…

"Let me get this straight…" He started to think out loud "There have been reports of: monsters, alien technology and aliens that look like brains running free in the city using robot armors and the weirdest one yet, from what the plumbers' satellites and witness saw, four figures that looked like turtles, using mechanical wings to get inside the mother ship then destroying it, thus saving the world…" He trailed of before shrugged "Not the WEIRDEST thing I've ever heart, but still pretty weird" He finished before enjoying the view from the window, while his ship was flying in autopilot…

Finally, after a long half hour, he arrived at New York, he landed his ship in an isolated area reserved for him by the Plumbers, then he active the camouflage mode and finally took his car to finally get to the city

Without a suspect about what he will find in the big New York City…

When he got to the city, he went straight to the apartment that was reserved to him. It was a medium sized place with a TV, bedroom with a simple bed for at most two, bathroom, kitchen and a laundry, it is located in a quiet place, not too far neither too close to a building called TCRI, apparently the place where the invasion started…

"Might as well start to gather info, no?" Ben said to himself before opening the window and started climbing up the fire exit towards the roof. After checking if no one was around, cause, even if the world now about aliens and stuff, he still preferred it when his powers were unknown to the world, no, better yet, unknown to the planet Earth! Now everywhere he goes, there are fans asking him to turn into a 'cool' alien and do tricks, girls asking him out, guys trying to be his friend. There was even a time some fans asked him to make OMNITRIXS to them! Or let them borrow his!

His life just lost whatever peace it had…

"Well, it is just like the old saying: no use crying over spilled milk…" He sighed before activating the Ultimatrix and searching for the right alien

"Four Arms, too destructive, Ditto, good, but if one of me get caught…Upgrade can be stealth, but magnet waves deal with him, Heatblast, would be a spotlight, hehe, no intentional pun, anyway the next one is… Perfect!" He finished before slammed the dial

His skin began to crawl as it hardened smoothed into something similar to an exoskeleton, yet not at the same time. It turned black as it raced over his body, blue blotches with lighter centers appearing all over him. His fingers became shaper as they turned into claws, and he could feel his toes melt into toe as a third claw sprouted from his heel with a loud grinding sound. His teeth fused together into two plates that felt like they could bite through almost anything as his eyes widened and became larger, turning a bright green with three dots. His muscles piled themselves up. He felt an itching sensation he got on his back and head. With a sudden, sickly sound, four large wings ripped out of his back, bigger than his entire body, and two large antennae burst out of his head. The wings and antennae flapped around for a few seconds before gently and silently wrapping around their owner like a cloak. The final piece of the transformation was a suddenly chilled feeling in his core, a feeling that ran through his veins and arteries that felt as cold as ice. The Ultimatrix symbol is located in the middle of his chest

"Big Chill!" The transformed hero said, before opening his wings and took flight, with his intangibility and invisible activated of course "I thought about using Ghostfreak, but if I find these turtles, I wouldn't want to scare them to death" He thought out loud

Ben\Big Chill flied around New York, getting familiarized with the city and admiring the view, since there hasn't had a sign of aliens so far

"Let's run one more lap before going back to-" Ben was interrupted by what sounded like… skateboard?

"Who is riding a skate board at 3 in the morning?" Ben\Big Chill decided to investigate it. Making sure he was still intangible and invisible before he started making his way towards the sound, founding this origin a few seconds later…

It wasn't what he expect, that's for sure

"Well… at least I know they aren't of Terraspin's species…" The alien hero thought while cautiously getting closer to his 'targets'

He sees four figures moving from roof to roof at a fast rate, appearing to be having fun without a care in the world while talking about what sounded like their accomplishment in the world salvation, Ben noticed too that these figures were human sized turtles, with hands, which destroyed his suspicion about them begin from the Terraspin's species, since said turtle alien doesn't have hands, they were all using masks and holding weapons… And another little fact that caught his attention is…

These turtles had features of human FEMALES! With the front of their tortoiseshell hugging their curves tightly

"I really did not see that one coming…" He thought with his face heating up a little while he observed the turtles. He noticed that the sound of skateboard was begin made by one of the turtle, one that had a orange with a tone of yellow mask, her weapon was two nunchakus

She passed two more turtles that were talking between themselves: one with a red mask holding two sais, and another with a purple mask holding a staff.

Finally, the fourth and last turtle appeared, wearing a blue mask and holding two katanas.

And based on what he heard, they were narrating their accomplishment in the world salvation

"Looks like I found the heroines turtles!" He shrugged before adding"Wasn't as hard as I thought it would be" Truth be told, he imagined that they would be hidden or something like that, not in the open talking with each other without a care to the world

The turtle with the red mask started "And then I took my sai and destroyed that Kraang!" The one with the purple mask responded "That's cool and all, but I used my intellect to bring down an inter-dimensional portal! Awesome!"

The blue masked one gave her opinion "What about Mistress Splinter? I wish I could have seen her destroy the Shredder!" She said before the three jump down to the sidewalk, where the one with the orange mask was and she started talking

"And let's not forget about the party cheese demon!"

"The party what demon?!" Ben\Big Chill screamed in his head, almost letting himself became visible again. But the red masked turtle interfered

"For the twenty-second time, Mikey. There was NO party cheese demon, EVER!"

The now named Mikey just crossed her arms and said "Did you see him?"

"NO!"

"Then how do you know, hum?" She returned, confusion the three other turtles and the transformed human

"What?! I- Didn't- That doesn't even make-" She sighed before showing a smile just to make Mikey stop before she turns insane "Sure, girl, Demon Cheese, whatever you say"

"We are awesome!" The blue masked one said before they continued to party and jump from roof to roof with the wielder of the Ultimatrix following them, that is, until the purple masked one asked a question

"Can we stop by April's?" The three other turtles stopped right away while she continued

"We are 1.3 blocks and six, no, no, seven meters away from her apartment" She finished while the others looked at her and the red masked one responded

"Yeah, that's not weird or anything, Donna…"

Ben could only think about one thing "Who is 'April'?"

A few minutes later they were on the fire escape stars of a three story house and Ben, still as Big Chill, was on the roof. The purple masked turtle now identified as Donna, knock the window "Visit for April O'Neil!"

"Gr! Did you really just say that?" The red masked turtle complained, just before the window was opened by a red haired girl, who seemed a little nervous around the turtles

"Hey, girls err.. great to see you all…" She greeted them, but before they could move closer to enter her house, she stopped them "Err… you mind staying at the fire escape?" She asked and the blue masked turtle said

"Seems like you've been avoiding us lately, April"

"It's not my fault, my father's fear of abduction is getting worse. He doesn't even let me out at night" then another person appears, a man with red hair

"I'm sorry, April. But what if the Kraang are still there, waiting.. I will anything to protect you!"

April sighed and returned "But, Dad, I can take care of myself now, and I will be with the girls, I couldn't be more safe!" April's dad started thinking, while he looked at the turtles, until Miket assumed him

"Trust us, Mr. O'Neil, those brains freaks and Sheredder are looong gone" she said, which all of them agreed but Ben, said hero felt something was wrong with that statement

"Unfortunately, I don't think the so, for some reason… I don't think so…" He tough while watching as April's father don't let her go with the turtles, but promised to let them hang out later. April is not happy about it, not even a bit, but she let it pass

The turtles started to move again, this time hidden and silent

"They are probably going to their home, base a something like that" Reasoned Ben\Big Chill "Better follow them, maybe now I will find out more about them" He fineshed as he fly behind them

"Wish I brought my camera, so I could see how Kevin would react seeing them. He he! There will have another opportunities for me" Ben\ Big Chill added as he keep following them…

To a deserted alley… Where they went straight to the sewers…

"They live in the sewers?" He observed "That is a good hideout… No one ever suspects the sewer, I don't know why, but no one does…" Ben\Big Chill thought while he watched they covered their trails, still unaware that they are being followed all this time

Now Ben, as Big Chill, is following them to their secret place in the sewers, seeing what more he can discovers about these human-sized turtles that appeared out of the blue and saved the world

"I really need to think of a better name to them…" He mentally sighed and sweatdrooped at himself "Forgetting about that, I can feel that they are close to wherever they wanted to go, just a little more and I wi-" Ben\Big Chill though was interrupted by a beeping sound "No! Of all times you could pick up to time out, you just had chose right this one, don't you, Ultimatrix?!" Ben\Big Chill furiously though, but his anger didn't last long, as the turtles heard the beeping sound

"You heard that?" The blue masked one said, picking her katanas and getting ready to battle, the others following her lead

"Who didn't?" The red masked responded before shouting "Whoever or whatever is here! Come out so we can beat you!" Silence was the only response she get

"I don't think that will work, Raph" Mikey broke the silence, but shut herself up when she saw the glare the now named 'Rafh' was giving her

But what no one of them knew is that Ben\Big Chill was long gone, he flew himself out of the sewers using his intangibility, now he was at the alley the turtles used to get to the sewers

"So close!" He thought, while he started walking towards his apartment, of course avoiding the people "Next time, how knows, we will get to meet ourselves, and maybe, become friends" He finished, only to starts thinking about what this adventure holds for him

Well, only time will tell this to our alien hero…

"One thing I can be sure: It will one unique adventure"

You are more right than you think, Ben. And I will make sure of that! Cause, you know, I am the writer of this story, so it is kind of my work and duty to do so...

Anyway, what do you all think?

Hum... Now that thought about it, I have two stories, so that means I will have double the fun?! YYYYYYYYOOOOOOHHHOOO! BOOOOYYAAAAAKAAASHHAAAAA! (just putting a little of TMNT, to keep up the suspence) The "Booooyakasha" is owned by Michelangelo from TMNT

Anyway, until next time, or chapter of

"Plumber between Ninjas" (What do you thing about the name? Maybe I will change, but for now, this one is good enough)

Human Soul out