Jenny is also equipted with state-of-the-art systems that contains large amounts of weapons for her missions, the flight system to take her battles to the skies (and outer space) and her body is made from an Titanium Alloy to takes large amounts of damage.
At the Wakeman residence in Tremorton, Dr. Nora Wakeman, a scientist is working in her lab when the alarm goes off. She turns on the monitor and sees there's trouble in the city of Metropolis.
"That's nothing, I'm sure Superman can.." Then she sees Superman being attacked by what appears to be an cyborg and a crystal in his chest cavity. She zooms in on the monitor and sees it's Metallo and the crystal in his chest is actually Kryptonite.
"XJ-9!" She shouted through the house's P.A. system and in a flash An six-foot blue/white robot came into the lab. The robot resembles a teenage girl with pigtails, a top and skirt.
"What is it mom?" Jenny asked.
"XJ9, there's a bit of a situation in the streets of Metropolis." Nora answered.
"Um....isn't that where Superman is?" Jenny asked. "Can't he handle the trouble?"
"Yes but it looks like he's in trouble. Look." Shows the monitor images of Metall beating up Superman.
"Who is he?" Jenny gasps.
"He is Metallo, one of the supervillains in Metropolis. He is a cyborg built by LexCorps and it's powered by a chunk of Kryptonite. You better hurry up before it's too late!"
"Don't worry mom, I'm on my way there!" And with that she takes off through the roof of the lab.
"USE THE DOORS NEXT TIME XJ9!!" Nora shouted as she made a hole in the ceiling of her lab.
On the streets in downtown Metropolis, Metallo has managed to defeat Superman with the Kryptonite-powered weapons. He approaches the weaking Man of Steel with the evil grin on his face.
"Looks like the Man of Steel is about to reach his end." He cackles as he moves closer, the radiation burned Superman. He raises his fist as it morphs into a blade and just as he was about to shove it in, an laser blast stops him.
"I wouldn't do that to Superman." a voice is hear, it was a teenage girl. Metallo turns around and sees what appears to be a blue/white robot that resembles a teenage girl.
"Well well well, if it isn't XJ-9." Metallo observed. "Robot fighter for Tremorton."
"You're not allowed to cause trouble here, and it's Jenny by the way." XJ9 said.
"Sorry Jenny, I'll get to you as soon as I'm finished with Superman here." Metallo said as he prepares to kill Superman with the Kryptonite blast but XJ-9 stood in his way just as he fired the blast into her but has no effect on her.
"Hmm...looks like you're brave than I though. Aren't you a little young to be fighting the bad guys?"
"Yes, but the way I see it, you're going down." XJ-9 said as she prepars to fight Metallo.
"As you wish little lady." Metallo replied as he grabs her by the hand and threw her across the street, crashing into an department store. But she steps out of the hole barely a dent on her.
"Is that the best you got?" she said as she fires her laser limb at Metallo but has little effect on him. "Nice try little lady." He cackled as the laser hits him on the chest a few times. "My body is stronger...stronger than Superman...and stronger than yours.." And he charges at the teenage robot girl again but this time she catches him off guard by slamming her fist of fury against his face, causing him to flip backwards and into a parked car. Metallo gets up only to move his jaw back in place.
"Very nice....but not enough." Then he grabs a streetlight and rips it out of the ground and swings it at Jenny, striking her like a baseball and sending her flying down the street and ripping up the asphalt pavement as she skidded to a halt. She got up and activates her shoulder-mounted Minigun and fires at Metallo only to have the bullets bounce harmlessly off his body.
"Perhaps you're not aware that I am Metallo!" he shouted as he grabs the minigun and rips it off her shoulder. She yells in pain as he then strikes her with the minigun, sending her crashing into three parked cars. But that didn't stop her as she gets up and picks up one of the cars and hurls it towards Metallo but her simply punches it into pieces.
"Is that all you.." Metallo gets cut off mid-sentenced when XJ-9 charges into him and they both blasted through several buildings in Metropolis before stopping at the block near LexCorps with Metallo laying on the pavement. Then he grabs XJ-9 by the ankle and flings her against the semi truck. He gets up and approaches her only to get blasted in the face by XJ-9's palm blast causing him to stumble back and she gets up and they both begin in a robot fist fight against each other.
The fighting lasted for thirty minutes before she knocks him a few feet away, their armor is battered but not damaged from the fist fight.
"It's over Metallo, surrender now!" She shouted.
"Over my cold...dead...body..." He replied.
"Alright, you've asked for it." Then her body transformed into a walking weapon with shoulder mounted guns to firearm laser guns to rocket launchers. Metallo picks up a manhole cover and just as XJ-9 fires her weapons, he holds the manhole cover in front of himself as she fires all weapons at him and the laser shots bounced off the cover and headed pass XJ-9 and hitting one of the tankers of the semi truck, causing a massive explosion in the middle of the street.
Metallo gets up and heads towards the inferno only to see XJ-9 laying on the street defeated and approached her.
"First I defeated the Man of Steel...Now the Girl of Steel." He said as he picks up the same manhole cover and raises it above his head. Suddenly XJ-9 slams her fist of fury into Metallo's chest with great force, causing him to be thrown back. He gets back up and notices that the chest cavity is empty and he looks up to see XJ-9 with the chunk of Kryptonite in her hand. She crushes it in her grasp.
"NNOOO!!!" He screams as he watches it turn into a pile of green dust.
"You little bitch!" Gets up and prepares to charge at her but he suddenly begins to stagger towards her, his body is powering down. Without the Kyptonight he'll shutdown. He crawls on his hands and knees and makes a desparate attempt to defeat her.
"You.....will.....pay for....." He stops mid-sentence as he suddenly shuts down, his fist stops mid-section towards her face and collapses onto the ground.
"XJ-9 thought battered and beaten but not defeated gets up and staggers towards Metallo's now motionless body. "It's Jenny.." She stated before taking off into the sky.