I originally was going to write a Bleach/ATLA however I wrote myself into a corner so instead I thought of just writing a Ben Tennyson Harem fanfiction in the ATLA world. I have read numerous Ben 10 harem stories so I wanted to give it a try. I hope you like it.

There will be lemon scenes later in the story. I want to install a decent plot in my story. Also this will be the first time I will write lemon scenes in the future so I am kinda nervous.

Ben's timeline will be post-Omniverse however his appearance will be from Alien Force and Ultimate Aliens and like Ultimate Aliens, his Omnitrix will have the ultimate function because it so cool.

This won't follow as faithfully as the show later in this story however there will be chapters that came from episodes.

Anyway the list so far is:

-Katara

-Suki

-Possibly June

-Toph

-Azula

-Mai

-Ty-Lee

If you have anymore ideas of girls in the universe then simply comment.

Last thing before the story is the appearance of Katara will closely resemble her appearance towards the end of the series.

Disclaimer: I don't own the Ben 10 or Avatar the Last Airbender brand or name. Any characters in the story with the exception of the OCs are not my creation. All trademarks belong to their respective owners.

X

X

Ben Tennyson, the hero and savior of the universe countless times over, has now experienced an unprecedented era of peace and tranquility after the events of Maltruant and recreating the universe.

"The job as a hero hasn't been fulfilling recently. At this rate, I'm unemployed." Ben breathed a sigh, muttering to himself, as he sits at his favorite smoothie venue sipping a chocolate and carrot flavor smoothie.

"My boy, if you want a job, I have one for you." Ben turned behind him to see the time traveler sporting his semi-new steam-punk outfit.

"Professor Paradox? What type of job do you have for me?"

The time traveler simply smirked.

"My, my, my boy. No witty comment, no exasperated response, you have grown a little since I last came here."

Now it was Ben's turn to smirk. "You have to grow up a little from what I have to deal with."

"Indeed, you will be heading to another dimension where technology is more archaic than yours as well as seeing the inhabitants have the power to manipulate the elements such as air, fire, water, and earth."

Ben Tennyson had a big smile on his face. "I would be lying if I said I'm not excited from this opportunity, but what is my purpose in that world?"

"You will have to figure out for yourself, my boy. I'm not giving any hints."

Professor Paradox took out his Chrono Navigator, his pocket watch, from his coat pocket to open up a portal which Ben took no hesitation to jump in.

Ben Tennyson came out to the other side of the portal to find a breathtaking view of the snowy tundra with the ocean reflecting the sunrise. What could make this scenery any better was if he was actually on the ground…he was at least a hundred feet in the air.

"WHY WOULD YOU PUT ME IN MID-AIR!" He screamed as he started fiddling with the omnitrix as he found the right alien to break his fall.

He slapped the faceplate as his bones started turning to liquid and his complete body was being turned into a slimy substance.

"Goo-!" Goop slammed into the ground before he was able to finish his own name.

He finally started pulling himself back together. Until he heard a sound of astonishment coming from his right side.

He saw two people looking like they were similar to his age; one was a boy with a ponytail and the other was a girl that had two braids along with her long hair. They had similar winter wear and their facial features looked similar implying they may be related.

Ben taking a closer look at the girl found her to be rather really pretty.

The brother and sister couldn't tell that Ben was in a moment of awe because of his alien form however the alien form did create a response from them…even though it wasn't the most positive of approach.

"Get away, you freak!" Sokka pulled his sister behind him while he took a defensive position.

Ok, time to diffuse the situation before the misunderstandings become worse.

Ben hit the omnitrix mark on Goop's center; transforming him back to regular Ben.

This made Sokka and Katara both wide-eyed with the new development.

"What are you!?" Ben taking notice of Sokka's question humbling replied.

"My name is Benjamin Kirby Tennyson, but you can just call me Ben."

He started to move closer to the pair while extending his hand internally hoping they have similar meeting gestures.

Katara didn't move back, but her brother forced both of them back as he still didn't trust this stranger."

"How do you transform to that weird creature?"

Ben simply pointed at the watch from his extended hand.

"This is called the Omnitrix. It allows me to transform into different aliens."

Sokka raised an eyebrow to his explanation. "Aliens? Aliens don't exist, stop lying to us!"

This denial would have made it harder for Ben to explain himself however helped came from the silent girl.

"I think we should believe him. You saw what he became. Besides if he was dangerous, he wouldn't take the time to explain it to us."

Sokka reluctantly calmed down as Katara started approaching Ben.

"Hi, my name is Katara, and over there is my brother, Sokka."

"Hi, my name is Ben…oh wait you know that already." Ben blushed realizing his mistake as he started scratching the back of his head which earned a giggle from Katara.

Katara taking a closer look at him saw he looked a little lanky but he had a firmed body. She realized why she could she his overall figure because even though he was wearing clothing that seemed alien to them; it still looked very thin to protect against the elements.

Ben saw Katara take of her winter overcoat.

"Whoa, whoa, what are you doing?!" He was panicking a little along with a flush face.

Katara was oblivious to the whole ordeal only caring about one thing. "Here, you need this more than me. It's very cold out here and I don't think your adequately protected."

Ben realizing the good gestured didn't want to take the coat because he felt like it was better to make sure that Katara didn't get sick.

Ben and Katara went back and forth with their argument until Katara finally got her way as Ben wore, as best as he could, the overcoat.

Ben told the brother and sister, as they walked back to their village, about the different world he lived in. The differences in technology and culture that flew above their heads.

They finally make it back, and Ben started to take in the sight of their home. "Wow, it reminds me of the artic nomadic tribes back home."

Katara hearing Ben's comment asked if they are an abundance like in this world however Ben disappointed her with the information that only less than one percent of the population takes in this lifestyle back home.

The sky started releasing black smoke spots; Ben seeing it landing on his face couldn't recall if there was something like this back home.

"Oh no…" Ben turned his head seeing Sokka's shocked look. He questioned him of the black smoke.

"It's suds… it means the Fire Nation is coming to raid us."

"Fire Nation?" Ben's confusion didn't last long as Sokka started grabbing on his winter overcoat's collar.

"YOU DID THIS! ARE YOU A SPY FOR THE FIRENATION?!"

"What? No, I don't even know what is a Fire Nation." Katara tried to pry Sokka's grasp on him.

"I knew we shouldn't have trusted you. You have to leave."

Ben Tennyson didn't run from a fight between the strong and weak and wouldn't start now.

"No way I'm leaving. I'm prepared to fight them to keep this place safe." Ben's gaze to Sokka was firm and unyielding.

Sokka finally let go of his grip with anger and frustration.

The warship of the Fire Nation finally made port in the village as the leader and his subordinates made their way down.

"Come out Avatar! I know you are here." The teen-looking boy appeared to be their leader. He was sporting a ponytail and a scar covering his left eye.

"I don't know who is the Avatar, but I was the one that came down to this village." Ben made his way to the center stage in front of the firebenders putting Katara's overcoat over her. Ben smiled to her in gratitude which earned a blush from Katara.

"A kid, a kid was what made the commotion?"

"I take that as an insult. How about this, I challenge you to a fight? If I win, you leave and never come back to this village." Ben gave the conditions of the fight.

"And if I win, I burned down this pathetic village along with you and the rest of them." The leader brought his fist towards the hero as fire erupted from his fist almost striking Ben.

He side rolled out of the way of the initial strike. That explains the manipulation of the elements.

"You are fighting the crowned prince of the Fire Nation, Prince Zuko."

"And you're fighting against the Hero of the Omnitrix, Ben Tennyson." He started looking through the omnitrix and found an old favorite.

"IT'S HERO TIME!" He smacked the faceplate as his body started to transform into a molten rock body, composed of a bright yellow inner color covered by dark red and brown rocking outer surface. His entire being was being surrounded in fire most notably his head. The omnitrix symbol being in the center of its chest.

"Heatblast!"

Everyone's eyes looked like they were going to pop out of their sockets when they saw this strange being's head burst in flames.

"I don't know what the hell you are, but your fire will be no match for mine!" Zuko set volley after volley after the Pyronite, but he just stood there taking the blasts.

Zuko was flabbergasted at his attack's uselessness.

"Is that it? I thought the prince of a Fire Nation will have tougher flames." Ben send a flamethrower of fire at Zuko which send him tumbling back.

Katara was thinking most likely what all the other villagers were thinking. "He took a firebender's fire and bended his own flame."

His soldiers seeing the turn of events took it in themselves to join the battle as they all bend flames at the Pyronite.

Heatblast moved is arms almost like a Buddhist deity as he controlled the incoming fire and distinguished it by putting his arms together.

"How about we change it up." Ben smacked the omnitrix symbol as he transformed himself into an aquatic looking creature covered in a red exoskeleton with an equally colored helmet-like head. His hands only had four fingers and had holes on each palm. He had other ornate holes around the entire exoskeleton.

"Water Hazard!"

Zuko picked himself back up as he saw this new being replacing the fire one.

"No matter who you change, I WILL WIN!" His anger erupted as he made a giant fireball towards the Orishan.

Ben raised both hands up and jetted a torrent of water against Zuko and his soldiers and send them flying back to the deck of their ship.

"And never come back." He jetted another to push the warship back to the water enough for the waves to send them back in the opposite direction.

Spectating on the warship's deck sat the Fire Nation legend, Iroh the Dragon of the West.

"You don't see that every day."

Katara saw the impossible; this unknown boy just transformed into a firebender and then a waterbender. She couldn't suppress her thoughts in her head as one word echoed out of her mouth. "Amazing." He could be the change that the world needs.

He transformed back to his normal self to see the conflicted faces of the villagers. The children were happy with Ben and his transformations, but Sokka and the other adults weren't equally positive.

"Okay you helped drive the Fire Nation away, you can leave now." Katara was furious with her brother.

"Katara, the Fire Nation will be back for revenge against him. We can't put the rest of the villagers at risk."

"But Sokka-" Ben interrupted their bickering to put his own two cents.

"No, you should listen to your brother, Katara. I'm a liability for the village and besides, I should have already left by now."

Katara seeing the sky was starting to get darker didn't want Ben to leave in the worsening climate.

Ben understanding her worries told her not to worry about him as he showed her the omnitrix.

Ben decided to find temporary refuge in a cave until the weather died down. Using Swampfire, he produced plants that could be slow burning as fuel for a fire. His hands were hurting; Katara was right that his current attire almost had no protection from the cold.

"For someone that defeated the raiders, you don't seem like you are in the best of shape." Ben was surprised to find Katara here in the cave.

"What are you doing here? You should be with your family." Katara looked down on the floor.

"My father left with the other warriors to fight in the war and my mother has been captured by the Fire Nation a long time ago. My brother is all I have left."

Ben felt a pain in his chest for opening something that shouldn't have been opened in the first place.

"I'm very sorry for bringing up a sensitives topic." Katara shook her head and smiled at him easing a potential aura of awkward silence.

She put her overcoat again over Ben which he was grateful. A few minutes passed, and Ben noticed Katara was starting to shake. "It will be better if you use it", he attempted to hand it back to her but she adamantly refused. I have no choice then. He made up his mind and moved closer to Katara so she can share in the heat.

She didn't expect him to do something like this. She was happy seeing him acting like a gentleman while she implicitly accepted his proposal; she got closer to him which made her face slightly red from the close proximity.

"So…I heard from a friend that send me here there were people who can manipulate the elements and judging from that fight, he was right."

Katara's let go of her nervousness as they started a new conversation. "That's correct. In fact, I am a waterbender; the last of the village."

"You can manipulate water? Can you show me?" Ben was curious to see waterbending in action.

You are not allowed to show of your bending or else you can be taking away. Katara was thinking of the elder's advice pertaining to her gift. She wanted for the longest time to learn and use waterbending freely without scrutiny. Now, she may now get the chance.

"Ok", Katara guided Ben out of the cave to see a small lake of water still not completely frozen as she bended the water out and back to the lake.

"You just manipulated water. You are awesome!" Katara's face brighten up over his compliment finally having someone appreciate her gift.

The weather was started to take a turn for the worst, and Katara was visibly more shaken than before. "It's not good catching a cold", Ben said while motioning for her to return to the cave.

They go back to their previous positions. Katara was curious of the brunette's goals. "So… what are you going to do now?"

"I don't know… I want to help the people of the world, but I don't know how."

Katara felt a realization like his goals were parallel to another. "You're like the Avatar, the wielder of the four elements. You want to bring balance to the world."

"I guess I'm like the Avatar. What about you? What do you want to do?"

Katara closed her eyes thinking of her goals. "I want to become a great waterbender. I want to be proud of my culture and not hide it."

Be proud of who you are…that's a very good goal.

"Let me help you become a great waterbender." Ben said with renew confidence, "and I will help this world by being their hero."

None of them realized Ben's motives brought them even closer, they quickly separating not wanting to give the wrong meaning. They stood in silenced until they both saw the fire slowly dying. Katara was looking around trying to find some fuel for the fire; Ben motioned her to stop as he activated the Omnitrix transforming him to the alien previously.

"Heatblast!" Katara felt the immediate heat from just being near him. "Check it out, I'm my own candle." He lowered the flames on his head proving his point which made Katara laughed at his joke.

"It's amazing seeing it up close like this." The Pyronite smiled as they continued talking about their past while Ben gave her more information about his hero business and the Omnitrix.

Time flew as they were busy talking with Katara finally feeling tired as she started to sleep for the night using her overcoat as a makeshift blanket.

Ben kept himself awake making sure he was still Heatblast to keep both of them from freezing from the elements.

He started to feel a little daze as slumber was slowly taking him as well.

"You seem to have a made…a good friend on your first day in this world, my boy." Ben eye's with wide opened again as he turned around in surprised to find Professor Paradox outside the cave's entrance.

"You don't usually come to monitor my progress as far as I seen."

"I'm just here to answer a few questions you have for me since you first came here."

Ben was smiling finally being able to get some information out of him.

"Why me…they have an Avatar in this world to bring peace."

Professor Paradox wasn't happy hearing his argument. "You know what happens when a society gives all their hope to solve the world's problems to one person. It will be chaos."

Ben found his answer to be contradictory. "What does that make me, the wielder of the Omnitrix, and the hero of the universe. Am I not considered a part of that problem."

This earned a laugh from Paradox. "My boy, you are mistaking. You may be a hero, but you are not the only hero we have. The universe has me, the Plumbers, and various other players in the universal stage.

"So my role isn't to be the sole savior, but to bring the people together to solve the problem." Ben theorized his role in this world.

"Correct, now that you know your role. Gather the people, save the world, and have a little fun while you do it. Ta-ta."