Ben 10 meets Batman

Disclaimer: I do not own any DC characters, nor do I own any Ben 10 characters. No profit is being made off of this story, it is purely for entertainment. Enjoy!

A/N: This story takes place before Omniverse, it is the direct aftermath of Ultimate Alien. Also, in this made up continuity the team never went through the whole 'Diagon' situation.

Chapter One: A Normal Day in Bellwood…
Ben Tennyson sits down and takes a sip of his smoothie, only to be swarmed by fans once again. He signs a couple autographs and shows off a couple of his aliens for show and eventually gets them to leave.

His girlfriend, Julie Yamamoto, sits across from him and asks if he's gotten tired of that yet. He says "Are you kidding? I wish it never started happening. Life was so much easier being a secret hero."

"Yeah, well, what can we do?"

Ben shrugs and slurps down his entire smoothie and burps.

"Gross."

"Sorry."

They sit in silence for about a minute and Ben says "Huh. Nothing bad has happened all day. It's starting to freak me out."

Julie attempts to tune out his idiocy when a giant portal begins opening up in the sky. Ben screams in joy and runs over to it. Julie mumbles and says "He'd rather fight a mysterious portal than be with me."

Ben looks expectantly up at the portal but at first, nothing happens. He begins getting disappointed but he hears a woman's high-pitched happy voice screaming "Weeeeeeeeee!" He sees a woman in a harlequin costume flipping out of the portal, followed by a man dressed as a clown. They land and the clown yells at her to close the portal before 'Batman' has a chance to follow them. She presses a couple of buttons and the portal closes.

Ben walks over to them and says "Who are you two supposed to be?" Joker shoves him away and says "Outta my way, pipsqueak. I've got havoc to wreak." Ben says "Oh yeah?" and he presses up the Ultimatrix. He spins it a couple times and slams it down. Nothing happens and he says "You have to pick now not to work? Really?" He gets up and charges at the Joker. He turns around and bitchslaps Ben into the wall. Joker mumbles and throws a pie onto a different building, which blows up. The clowns run away and Ben's Ultimatrix begins working. He shouts in joy and presses it down.

"FEEDBACK!"

He shoots his electrical wires from his head and wraps them around the Joker's arms. It shocks him but he is able to redirect the electricity into his joybuzzer and he shoots back at Feedback. It hits the Ultimatrix symbol, which transforms him into Ripjaws. He looks down, confused and the Joker and Harley Quinn begin getting away. He says "I am not losing to a clown!" He presses the Ultimatrix symbol and turns into Heatblast. He says "Oh yeah!" He blasts fire and puts a cage around Joker and Harley Quinn.

Harley asks Joker what they should do. He says "When in doubt, leave you sidekick behind." He jumps through the fire fast enough to not get caught on fire. He throws another pie at Heatblast and it hits him in the face. It blows up. When he gets up he has timed out and the Joker got away, but Harley Quinn is knocked out as well. He looks around and Mr. Smoothie is nearly destroyed. He sighs and says it is going to take forever to clean this up.

After making sure everyone was okay and turning in Harley, Ben goes to Kevin's garage, where he knew Kevin would be working on his car. He sees Kevin's feet and tells him to get up. He rolls out and says "There'd better be a renegade alien on the loose."

"Something like that. A giant portal opened in the sky and these two people dressed like clowns came through. I caught one of them, but the other got away."

"Clowns? And one of them beat you? HA!"

"I'm serious! He was able to take down Feedback, Ripjaws, and Heatblast!"

"Oh come on, I could take down Feedback, in human form."

Ben mumbles something to quiet for Kevin to hear and asks if he is gonna help track him or not. He tells him to go to Gwen, because he is too busy installing photon drives. Ben asks what that is gonna do. Kevin looks at him and says "It will let me convert this car into energy, allowing it to move next to the speed of light." Ben stares in shock and says he is gonna go to Gwen.

He arrives at Gwen's house and she answers the door. She asks what's up. He says "I need your help tracking someone."

"Do you have anything I can track them with?"

He pulls something out of his pocket and says "I have this pie frosting that he was using as a weapon."

Gwen looks at him skeptically, but she gives in and tracks him. After about a minute the frosting drops and her eyes widen. She says "He's gone to the Forever Knights castle!"

Ben's car arrives at the castle and Ben, Gwen, and Kevin get out. The Joker is standing outside of the castle and Kevin says "So that's the guy who took down three of your aliens?"

"He's more powerful than he looks."

Joker walks towards them and says to Ben "Come back for more?"

"You shouldn't trust the Forever Knights. If you've made any kind of alliance with them-"

"Oh they're not the only ones I've made an alliance with that I shouldn't trust."

He motions towards the doors. They open and an army of Forever Knights walks out, as well as Overlord, Albedo, Dr. Animo, the Circus Freaks, Ssserpent, and Sunder. Joker begins laughing like he has never laughed before. He then motions towards the Circus Freaks and says "They're my personal favorite."

Kevin says "We're screwed." The Forever King yells "CHARGE!" All of them begin running towards the trio. Ben turns into Chromastone and Kevin quickly absorbs the crystals on Chromastone. They charge into battle as well.

Chromastone takes out several Forever Knights and blasts lasers at several more. He is tackled by Albedo, who has taken on the form of Rath. They begin brawling but when Rath gains the upper had Chromastone realizes he will never win like this. He presses the Ultimatrix symbol and yells "ULTIMATE CHROMASTONE!"

He punches Rath in the face and he is out like a light. A Forever Knight blasts him in the back but the laser immediately redirects itself back at him. The Circus freaks are pulled aside by the Joker and he says he has a special mission for them.

Gwen notices the four clowns getting in Ben's car. She tries to run after them but she is tackled by several Forever Knights and Overlord. Kevin is blasted several times by Forever Knights, but having absorbed Chromastone, he blasts the lasers back at them. He screams in joy but he too, is tackled by several Forever Knights.

Joker hotwires Ben's car and they drive away. They arrive back in Bellwood and go to the Police Station. They break in and Frightwig takes care of the guards. Thumbskull walks over to a cell holding a blonde woman with pig tails. Joker tells him "This is the one." He rips the cell doors off and the woman runs at the Joker hugging yelling "Mista J! You came back for me!"

"Of course I did sweetheart. I wouldn't leave you here."

Back at the battlefield the villains keep advancing and Gwen, Kevin, and Ben (who has transformed into Four Arms) gather around each other. Gwen creates a force field around them and says they can never win like this. She screams "ABEO EXORIOR!" The three of them begin to blur until they disappear completely and the force field dissolves, leaving their attackers all alone.

The three of them appear in the middle of Bellwood, only for another portal to appear in the same place it did last time. Ben sighs and says "What is it now?"

Soon enough Batman comes jumping out of the portal and he lands with ease. He gets up and says in a very threatening voice "Where is the Joker?"