Disclaimer: I don't own Ben 10 and Teen Titans

Me: Hello everyone and Welcome to another crossover of the Cross Dimensional Adventures of Ben 10. But this time Ben crossovers with the great heroes of Jump city, the Teen Titians. Before you read this story please read my other crossovers like 'the cross dimensional adventures of Ben 10: Hero meets Phantom' and 'the cross dimensional adventures of Ben10 :before the crossover.' I hope you all enjoy this chapter and if you see any error please inform me nicely through a review.

Chapter 1: Welcome to Jump City Part 1

The sun rose from the horizon of the fair city known as Jump city. This great city had people working out their normal lives and whatever may come they way, but there is some things that they can't handle. For one they're usually attacked by super villains, evil masterminds and brute forces that normally attack this city to cause trouble or take over the world.

The city had gone through many unspeakable things and is surprising that the people are calm, but that is because they had heroes. Just like other cities like Gotham, Metropolis that have their heroes, this fair city has super powered teenagers as they heroes. These superpowered teens are the great team that had saved the world from many disasters such as super powered freaks disturbing the peace and invasions, stopping the brother hood of evil and so much more. These great heroes formed together to help the world each with their unique abilities and together they are known as the Teen titans.

As the Teen titans they had faced danger of all shapes and sizes, but the question that will soon be going on our minds is that….are they ready for what is to come or will they finally meet more than they match.

(LINE BREAK)

High above the city of jump city was a space ship known as Dimension Doomsday. The ship also belongs to one being known as Nefarius though nothing is known about him except that he has a hunger for power and will do anything to gain it even if it means killing an entire city.

Deep in the ship and in its throne room that had a vast space and at the end has a long stairs with a person dressed in Dark robe that hides his entire body except his palms and his human looking lips and was sitting on a golden throne chair.

He seems to be in his thoughts and was waiting for the reports that he needed to know. He left his throne and walked down the stairs then he saw a ghostly knight walk to him and bowed down.

"Master Nefarius we have the reports." Said the ghostly knight.

"Good Fright Knight." Congratulated the being, "so what are the threats of this world?"

The ghostly Knight stood up and waved his hand and immediately a giant screen appeared on the air.

"This is a world habited by super humans and freaks from different worlds. In this universe there's super human that are both good and evil and according to my report there's a team called the Justice League." Just as the Fright Knight informed him, an image of the Justice league appeared, "but we won't have any trouble from them yet."

"Good so this will be easy."

"Actually no master." The Fright Knight waved his hand at the floating screen and it changed to an image of five teens with different super heroes costumes.

"And who are they?" asked the being.

"The city we fly above is known as Jump city and its heroes are these teens." The Fright Knight gestured his hands to the screen, "The Teen Titans are its heroes and our reports has confirmed that they are an enemy to all that threatens their city and also the world."

The fright Knight was silent and glanced at his master. He couldn't tell what he was thinking or what is expression was mostly because of his disguised.

"What must we do Master." Asked the Fright Knight.

The evil being smirked, "Simple my dear Fright Knight. We test how worthy they are so rally up our newest allies; we have a lot to do."

The Fright Knight obeyed and walked away and heard his master shouted out.

"Nothing shall stop I Nefarius soon to be ruler of all dimensions!"

(LINE BREAK)

In an alley in Jump city, a portal appeared and a teen stepped out. His dressed in a white shirt with a black stripe that goes from top to the bottom, green baggy pants, has green eyes, brown hair, a satchel and a strange watch on his wrist.

He walks out of the portal and gazes at the busy city of jump city. He glanced at his hands and noticed that it was more 3D than previous Universe.

"It's hero time." He muttered before walking off

Ben 10

(Cue Ben 10: Race against Time theme song)

Ben 10

Meanwhile on a T size building on an island was home to the heroes, Teen Titans. It been a month since they had beaten the Brotherhood of evil and peace still reigned in Jump city.

Shortly a week after they had beaten the Brotherhood of Evil, there hadn't been any crime. The teen Titans leader, Robin thought it was suspicious and so they checked things out and confirmed that all villains were either behind bars or were missing which made Robin more suspicious. So during the last few weeks they had been on the alert to confirm any ambush on them or the city.

In the living room/briefing room of the Teen Titans were Beastboy sitting on the floor and changing the channel with a bored face. Every channel that he changes he would say boring over and over again. The remote he was holding was then engulfed in black energy and flew off his hands and landed on a female's hand.

He glanced at the girl. She wore a purple cloaked with the hood covering her face and in a meditation position on the couch with a book in her hand.

"Hey I was using that Raven." Beastboy complained.

The girl known as displayed to him in her hand.

"Can't you be any quiet?" asked Raven as she was hiding her anger.

"Well excuse me, I bored okay. I don't have much to do. You all have something to do like CY is modifying some stuff, Robin is training and Starfire doing what she normally does and you're meditating."

"Then why don't you just head outside." Raven suggested as she was about to leave, "Take some fresh air or something." She tossed the TV remote back at him and went to her room.

Beastboy sat there thinking of what she said. The idea was not one he would normally go for, but he preferred that than flashing channel after channel, but before he could act a teen mostly covered in robotic machinery came in.

"Hey BB." Greeted the guy, he glanced at the TV and then him, "Your bored aren't you."

"Oh nothing gets passed you CY." Said Beastboy sarcastically.

"Anyway can you get the others I have something to say and show?" Asked Cyborg.

"Sure whatever." Replied Beastboy as he got up.

Beastboy POV: 10 minutes later.

After getting everyone else we were in the briefing room. Starfire was sitting close to Robin, Raven was sitting as far as possible from me, I think she's still angry at me about earlier.

"So you maybe all may be wondering why I got you all here, well I just designed these.." CY brought out five yellow –black watches.

"What are those?" asked Robin.

"These are our new communicators." Cyborg answered, "with these we can communicate with each other, track wherever we are on the planet and it runs on solar power."

"And that's it." I asked bored.

"Well why don't you try one." Cyborg asked with a grin that made me think that there was something I wouldn't like. He tossed the watch and I grabbed it and set it on my wrist and immediately I couldn't see my hands and then my whole body was gone.

"Wow I'm invisible!" I exclaimed.

"Yeah it's also makes someone invisible so if we're undercover then that would be useful. It can also make a force field and best of all has the best Mp3 songs in the whole world and has many more features."Cyborg explained.

Robin stood up, "Great work Cyborg these will come in great use."

"Yeah Thanks friend." Starfire congratulated him.

"Hey this is all fun and all, but I have one thing to say." I asked as everyone turned to my direction, "HOW DO I BECOME VISIBLE AGAIN!"

A few minutes later of being visible again I was once again bored, so for once I decided to do what Raven said.

"See you guys later I'm heading out." I said before leaving the T tower and turned into a hawk and flew off.

(LINE BREAK)

Beastboy POV

I was flying above the city as a hawk and for once in a long while was at kind of nice. I enjoyed the little breeze that was pouring upon me and looking down at the city. from above it looked like the people were ants though I know they're not, but then I was interrupted by sirens of squads of police cars and I flew lower to view what was going on.

From my point of view, I could see that a section of the streets were thrashed and a squad of police officers cars formed as a blockade trying to contain the situation. I then flew down beside a woman officer and tap her shoulder and she jumped a bit surprise.

"Excuse me, but what's going on?" I asked.

The woman turned to me and seems relief of something, "Finally you guys are here. The city is under attack a giant block like creatures."

"Where is it and how long has it been the fight?" I asked, I was curious of how long it has been.

"Two hours." She answered and then I was confused, how were the Teen Titans alarms go off, what's Cinderblock during and who could be behind this.

"Don't worry I'm on it." I assured her to a smirk. I shape shift into a hawk and flew off to the center of the main trouble.

From high above the air, I could see a SWAT team trying to take down Cinderblock, but unfortunately it was useless. Every shot of their fire arms they fire they couldn't take him down. Cinderblock carried a van and threw it to an armored van that was surrounded by armed SWAT teams, but they ran out of the way. It was getting too much out of hands as it seems that Cinderblock is determined to destroy everything, so I decided it was time I stepped.

I flew down to the street and got some of the SWAT team out of the danger, some of them were reluctant, but then they listened and left me to face him. Then I turned to face Cinderblock who had seemed to have paused for a few seconds. Looking at his height and builds made me wish I should have worn Cyborg watch communicator instead of leaving it back at the Tower.

"Okay maybe I can do this." I tried to assure myself, but then I was proven wrong when he charged at me. I reacted quickly and transformed into a hawk and flew out of the way.

I tried flying above so I can have a higher advantage, but he caught me his hand and threw me to the ground hard. It sudden impact to the ground caused me to transform back to normal and it also caused me to be dizzy. A groan escaped my lips as I tried to get up, but then I noticed that a huge shadow covered me and I glanced up to see Cinderblock foot about to squash me. I wouldn't be fast enough to escape so I closed my eyes so I won't see what will happen next, but then I felt someone grab onto me and flying higher. I peeked open my eyes and to my happiness it was Star.

I was thrilled that I had just escaped being killed but all that changed when I looked over her shoulder and saw a car flying towards us. I couldn't warn Star as the car had already hit us and we fell to the ground. I felt pain coursing throu8gh my building but despite that I got up and helped Star to her feet.

"Star, Star speak to me." I called out sacred. I wouldn't forgive myself if she got killed all because of me and I'm really sure Robin won't either.

She answered weakly, "Beastboy?" I was really glad now that she was safe.

I got her to a better position to carry, "c'mon I got to get you out of here." Star tried to struggle out but I wouldn't allow it. Then suddenly we felt the ground begin to shake and then it occurred to me we forgot about who we were fighting because I could see him charging towards us. I couldn't think of anything to do, but then I was surprised to find Star fly out of my hands like a speeding bullet and gave a powerful blow to Cinderblock that sent him flying off course.

"Wow." I could say as Star flew to me.

"I only kept him for a while we need help." Said Satrfire.

"Okay so here's what we'll do…" I was cut off from an unfamiliar sinister laughter. We turned to the direwction and standing a few meters from us was some guy in a dark costume that disguised his entire body.

"Who are you?!" I demanded. I stopped laughing for a moment and continued. For some reason it sent shivers through my spine. Knowing that we may be facing some super villain I got into a fighting stance and Star charged up her star bolts with her eyes glowing.

"My friend asked you of who you are, so answer!" Starfire ordered. The guy stpped laughing and concerntrated on us though I could see a grin form on his lips as that was the only unhidden thing that I could identify.

"I wouldn't be worrying about my identity if I were you." He then pointed at us, "But the girl behind you on the other hand." He laughed sinisterly as we turned behind us and saw Blackfire hovering on the air above us. Her hands were glowing as it was charging up Blackbolt and a grin on her face.

"Hello sister." She fire two blackbolts at us but we ducked out of the way. I got up to help but then I was pushed to the ground by a sudden force. I tried standing again but the force came back and this time I found myself being twirled in a blue and black blur tornado and finally crahjed on the ground hard.

A groan escaped my mouth as I turned my head to the other side and saw Blackfire and Starfire engage in a fight. It didn't worry me much anyway, Stafire had kicked her butt many times, so that means I just have to deal with what was the strange force.

"Get up!" I heard a voice yell at me. I got up and glanced at where the voice came from and it looked like some kind of creature. It looks like a semi-armored velociraptor with wheels under it's feet and a helmet.

"Dude who are you or what are you?" I asked.

"Doesn't matter green boy because I'm going to make you hurt." Replied the creature. He ran in superspeed and I couldn't reaqct as he punched me in the face and gave me a round off kick that sent me flying to a van.

I stood up and spit out some blood and focus on the fight. If the wants a fight I'll give him a fight he'll never forget.

Starfire POV

I was fighting my sister, Blackfire. She seems to show great skills from our last encounter and wasn't even trying to hit me, but I wasn't going to let my guard down.

"What are you doing here?!" I yelled angrily at her as I summoned a huge starbolt at her. She didn't bother to move, it hit her but nothing happened it was like there was something invisible in front of here. Then I was surprised to see a hand became invisible in front of Blackfire and attached to the rest was Cinderblock.

'Cinderblock was unseen. How is that possible' I thought to myself.

Cinderblock dropped his hand and I was able to see my sister again with a grin.

"You seem surprise little sis." She smirked, "But guess what I found." She brought out a red jewel, a jewel that I had crushed was now in her finger tips and in one piece like nothing had happened to it and that made me show how shocked of seeing it, "surprised Kori, then good because now I'm going to finish you off and this time it is more powerful than it ever was." She placed it on her colar and immediately she was covered in the jewel's power.

"Get rid of it!" I yelled at her, "It's no good to you."

My sister smirked, "Oh really, then I'll just have to prove you wrong." She charged up a huge red bolt and fired it at me.

Beastboy POV

This was getting bad. I tried beating this guy but it was no use. I tried my hitting this guys, but he would either dodge my blows or would encounter my attacks.

I shapeshift into a gorilla and knocked the ground which caused the ground to crack and he fell. I charged towards him and threw my hands down at him, punching and blowing him. I then grabbed his foot and knocked on the ground twice before twirling him in the air like a lasso and threw him to crash into a store.

I reverted back to normal and walked towards him really sure that I had taken him down. It was a satisfaction that I had taken him down though the questions kept rising on my mind. Who was he, why was Blackfire here, who was that mysterious guy with the evil laughter. It was all those questions that kept bumbling in me, but then I was cut short from my thoughts a fireball nearly got to me if I didn't jump out of the way.

I got up and looked at the store and a light figure emerges out. He was mostly made of flames and rocks, but then it occurred to me that isn't that where I threw the fast speeding guy.

"I'm going to burn you to a crisp!" the flaming guy yelled angrily. He fired fire balls at me but I kept on dodging them. I wasn't really the best at dodge ball or in this case dodge flame but I was beginning to tire out. I had to think on how I could beat this guy without getting burnt in the process, so I turned into a T-rex and charged at him.

The flaming guy kept on shooting at me, but I was able to dodge out of the way. I nearly got to him, but then he flew up. I looked up and suddenly I could see he created a huge fire ball and shot it down at me.

Starfire POV

I wasn't going to lose to my sister, I haven't before so why now. The only problem now is that she's wearing the Jewel of Charta and wouldn't rest until she was satisfied on killing me. It made me to think on how I had seen other sisters when clothes shopping and how happy they looked it just made me sad though I didn't let any of my friends know.

I was just lucky to dodge her first blast, but then she went mad. Her whole body was glowing with the power of the Jewel of Charta. She was firing more of red energy bolts and it was getting too much. I was able to avoid some of them, but some nearly had me. This showed to me that the jewel true power has been tampered with.

"STAY STILL!" Blackfire yelled. Suddenly she was engulfed in the power of the jewel and she sent down red lightning bolts at me. I tired my best to avoid them but eventually it got me and it hurt a lot. I could feel it hurting my entire body and it felt as though I was dying and I couldn't do anything about it. I tried resisting, but it would seem my sister really wants to do away with me, but then I felt it stop. I opened my eyes and found Blackfire holding to my throat.

"Nighty, night sis." She grinned and charged up a red bolt and punched me to the face. It sent me falling down to the ground and I finally made contact to it and blacked out.

Beastboy POV

I couldn't take it anymore. The flaming guy first blast nearly took me down, but then he shot fire down at me. I shook it off and tried to keep the pain from hurting any better, but it was no use the flaming guy kept on firing and firing that I couldn't stop. I heard a scream I knew that was Starfire. I couldn't save her as of now I was the one who needed saving. I then felt the ground shake and I glanced at where it was and it was Starfire who had now fallen.

"What's the matter…scared." taunted the flaming guy, "when we're down with you, we'll go for your friends and maybe they'll show a little fight in them."

I roared at him angrily and proceeded to get him. I wasn't going to let that happen, but then he shot out the biggest fire blast and I couldn't take it anymore. The burns were already getting to me and I could feel my strength draining.

I weakly reverted to normal and collapsed on the ground, but still conscious. I could see the flaming guy laugh out and Blackfire and Cinderblock meet.

"Look at them and I was looking into a real fight." Grinned the flaing guy.

"Then I hope you're ready for a real butt whooping." said a male voice. I glanced at who it was that said that and it was a teen. He was dressed in a white shirt with a straight stripe, wore black and white shoes, has brown hair and green eyes.

"Tennyson!" hissed the flaming guy, "I'm going to kill you for what you've done to me."

I tried to shout out that he should run, but my voice was only a whisper.

The Boy as the activated a watch on his wrist and a green hologram appeared, "Going Hero." Said the boy as he slammed the watch.

(LINE BREAK)

Me: hope you all like it. I feel like I made Beastboy and Starfire a bit out of character, but don't worry I'll improve that later on. Please remember to leave a review and constructive criticism are always welcome, but no flames.