A/N: I'M BACK~!

For those who've read and liked this story so far, THANK YOU~!

I own NADA at all. Just my self insert OC as well as the changes I made just for this story. Hence AU.

WARNING: This chapter does contain some swearing/language further down along as well as some bloody stuff ... you'll see.

But I do hope you enjoy!

The constant punches from Humungousaur against a Block Party shield caused the ground beneath Rex to cave in piece by piece, creating a small crater in the process. Rex kept his eyes shut, knees bent but staying firm in place as the Vaxasaurian pulled back.

"Stay down if you know what's good for you!" But just as he growled out the warning, turned around and started walking away, his green eyes caught sight of a figure watching them from the tree line, peaking from behind a tree trunk. He could have sworn he spotted them waving at him. Quite shyly, too.

"I'll show you what I'm good at, feo!" Rex quickly switched to his Punk Busters and pounced on the distracted beast; the giant boots plus the spikes on the heels striking the beast chest first as it turned around but too late to prevent the blow.

"Rex, I'm getting more fluctuations in the event. Something's coming out." Holiday informed through Rex's COMM as just as its spoken, a mechanical beast with whiplashes for arm limbs springs from the rift, landing hard enough to create a shockwave to knock away the Providence vehicles that arrived on scene before pushing off from the ground and soaring at quite high altitudes.

"I see it, Doc!" Rex spoke loud and clear as Humungousaur got back up, noticing the mystery figure was gone; probably hiding among those trees or was probably just a trick of his mind.

"You and your partners call it quits right now … and I'll keep the pounderizing to a minimum!" He pounded his huge fist into his other giant palm, menacingly approaching Rex.

"I was gonna say the same thing … only in Spanish!" He then switched to his Smack Hands, landing one of them right at the beast, making him spin in mid air before crashing into the park's statue. "You take the hunk of junk, Six. Big ugly is mine!" He watched as the ship Bobo stirred with Six in tow followed after the other rampaging beast.

"You want to learn the hard way? Lesson one: dangerous aliens are not welcome on my planet!" After brushing off some rock debris from his shoulder, he joined his hands together once again before slamming the ground; causing a row of giant sharp rocks to break free from the ground and come speeding towards Rex who was able to jump high enough and off to the side.

"I should put a stop to this … but this crossover fight is so iconic and my favorite … oh gawd, but people are gonna get hurt. But if I get too involved in this, it could make things worse and the outcome could be dire … but damn my man can be so fierce it's intoxicating~!" G tried reasoning with herself, only to end up blushing and swooning as she watched her monster man fighting the robot dude she were really liking in person as she sped walked while following them.

"Rex, there's more. Our special guest literally teleported out of the ship." Holiday informed.

"What!?" Rex exclaimed.

"She didn't use a rift like Breach does with her abilities. She's in the vicinity near you."

"Aw, come on G. Work with me here." Rex muttered before grunting loudly as he got smacked due to him now being the one that got distracted. He soared through the air, skidding through the surface of the lake before sinking into it. lake. He undid his build as the excess weight would just drag him down; surfacing as he coughed out some water leftover in his mouth, rubbing his sore chin as he put his fists up at his opponent who trudged through the waters. "You can punch, I'll give you that."

"You alien wannabees should know better by now. Mess with Ben, you get the 10!" Humungousaur wasn't suited for the water.

"Aliens? The 10? Great, another insane EVO. Providence is all over your … energy weapon whatever. So, let's see if I can't knock some normal back into you." Rex smirked as he dipped down, submersed beneath the lake.

"Good luck with that." As he growled out those words, the sound of a twig snapping made his gaze snap over to seeing the same figure from earlier start to reveal themselves from the shadows between the trees across from him. In those few moments, he recognized the familiar attire. That loose white tee with the black zentagle heart design. The worn out jeans. Those white sneakers with blue and pink tie dye. "Can it be – UH!" A whip wrapped all around him, pulling him down under.

But under water, a bright green light flashed out, followed by a new beast appearing out of it and above water; a more diamond based creature; a Petrosapien. Using Blast Caster's tentacle-like whip to get a hold of his opponent, Rex sprung out from the water to jump on his back, reaching his left hand over to touch the circular green and black piece of his chest. His hand glowed a bright aqua blue and white light as matching circuit lines appeared all over his lower arm and hand, putting his nanites to work … only for nothing to happen. "Okay, that's weird."

Diamondhead pulled him roughly over his shoulder, getting him off and about charge ahead, when he staggered and almost fell over. He held his right arm; his throwing arm, as it felt stiff and tingly like it fell asleep; those glowing veins of Rex's w still there and trailing over most of Diamondhead's right arm and the right side of his chest. "What did you just do to me?!"

"Not sure … but I like it." Rex drew his Big Fat Sword whereas Diamondhead was still able to form a big enough diamond spiked one to even the playing field. Rex jumped up high to strike down and the sword duel had begun. "Holiday, are you seeing this? Creature feature just went BLING on me!"

"Be careful, Rex! This is something we've never seen before!" Holiday's concerned tone was soon overtaken by the splash of water as Diamondhead swung his weapon down; Rex narrowly dodging in time.

The explosions made in the city backdrop behind her made G groan in dismay. "Staying on the sidelines in this setting is making me feel guilty already! But with Six handling Alpha, Providence blasting their beam on the rift bubble, and those two cuties brawling, I should pitch in. As far as I can push myself." She looked back to the guys, frowning but with longing eyes for her beloved, "For them." She then ran into the city, dreading what would soon come.

000

How they went from fighting in the lake to atop a city building to crashing onto the Manhattan Bridge, Rex did not know. But what he did know, floating down with help from his Boogie Pack, before landing and going back to the BFS, was that he was wiping the floor with this guy. Literally. The diamond dude crashed through the row of empty parked vehicles, grinding into the ground, coughing out the bitter taste of pavement. "Lucky punch."

"Don't believe in luck. Now, hold still so I can cure you."

"You're talking crazy! And I'm NOT sick. We're wasting time!" Especially when he wanted to find that familiar looking person from earlier … if its who he thinks it is then oh gawd – ! He slammed the watch symbol on his chest, bathed in the same green light, before it dimmed down – to Rex's gobsmacked expression – a new creature; a Biot-savartian. Lodestar, to be precise. "Metal, meet magnetism!" Projecting green magnetic waves from his chest, it pushed Rex's sword back to the point where it forced itself to be undone and revert Rex's arm back to normal.

"Magnets huh? Well, there's no metal in pavement!" He barked out as he formed the Slam Cannon, loading up on ammo from the wrecked bride road, before firing one big one; hitting the mark as Lodestar yelled out crashing through the other half of the long bridge, carving through more pavement and vehicles as fire and smoke came out of the wreckage.

The next thing they know, Lodestar soars through the air towards atop a building, crashes through one of the steel supports for the billboard atop said building, then slams into another steel support very head by his back and head. "Ow!"

The billboard sways a bit as Rex lands with help from Boogie Pack, again, smugly satisfied having cornered his foe at last.

But things never seem to go right as the Providence promoting billboard falls from the loose support and unto the innocent populace down below that scattered away.

"Time out! Innocents!" They both exclaimed at once, to which both exchanged long stares, before Rex sprung into action just as Lodestar slammed the watch symbol yet again. Building the Rex Ride and speeding down the building just quick enough to catch a running women and pull her atop his seat just before the billboard crashes to the ground. But as the people around them screamed in terror at what was coming after, Diane Farrah and her camera man were about to look up to see what was the cause of the panicked crowd when one tall lady tried pulling them out of the way from behind.

"Move it, people! Move it!" Diane looked behind her to see the brown haired, brown eyed gal – G – demanding them with a panicked expression, sweat beads on her forehead, as she managed to yank them back with enough force. But before she could teleport them all out of that particular spot, something else pushed them out of the way just in time before the steel supports stabbed the ground. Something – or rather – someone large, strong, and quite furry.

G groaned out a bit from the pain of the rough impact as her eyes creaked out. Her fuzzy vision began clearing when she felt an ample warmth pressed between her bosoms; the familiar glowing green and black symbol, making her immediately internally swoon as she did her best to hold back a moan despite how it good the sensation felt. While Diane and her cameraman were pressed on either side of her as she was in the middle of their big furry arm cage, G's attention was solely focused on the Appoplexian looking down at her dead on; her face burning up in bashfulness from his narrowed gaze. But then, his big clawed paws moved to wrap around her waist, pulling her up along with him as he stood up, hoisting her up in the air and towards him so their faces were mere inches away from each other.

"Um … hi." Her cheeky smile barely hid the nervousness she felt. His low growl and the carnal desire look in his eyes made her gulp as that burning sensation from earlier returned, causing her heart to pulsate like crazy and butterflies rock her stomach as that warmth then traveled downwards –

"Thank you … you – who are you?!" Diane interrupted the moment, her camera man keeping a firm grip as he filmed.

He growled as he put her down before facing the curious reporting duo. "Seriously? I'm the cat whose all that! The Rath Attack! And about a hundred other things." As he shouted, poised and pointed out, G was so lost in the moment, infatuated by the presence of her favorite alien of his, that she forgot something. Something crucial.

Like Rex's Punk Busters landing on Rath, making G fall back from the force it gave off, burying Rath deep into the cracked road. "Time in!"

"What the hell, Rex!?" G let out a snarky remark on impulse, pissed at herself for getting too caught up in her euphoric mindset from watching her man and upset from Rex burying him and almost hitting her in the process.

"G!" He was relieved she was alright but now frustrated from what Doc informed him of and from himself for letting her wander about unsupervised and doing who knows what. "I'll deal with you after this." He undid his build, landing before a scuffed up Rath. "Thanks for the assist … but say adios to your nanites for real, el gato!" He reached his hand out to Rath; his gloved hand glowed with the same circuit lines as before, but once again to Rex's shock, nothing happened. No EVO to cure back to human form. Something was definitely wrong here.

Rath opened his eyes up at him before pulling himself out of his ditch, back flipping and landing a bit away. He shook his head to shake off that strange after effect Rex's powers did to him. "Will you stop that!?" He suddenly felt gentle hands on his shoulders, making his head turn around to see G's tall form lay against his squatting form, now wrapping her arms around his neck then nuzzling her cheek against his fuzzy one. Rath couldn't hold back his pleased deep purr.

"G, what are you doing!? Get away from him! He's dangerous!" Rex yelled out, disturbed by the sight.

"I will not! He's not a threat! He's not even an EVO!" G protested.

After failing to cure the dude, twice now, it actually made sense. "You … you're not an EVO!?"

"Let me tell you something, robot boy! I have no clue what an EVO is! I'm just tryin' to do my thing!" Rath finally stood up, making G pull away to shift her position to standing beside him.

"Destroy our city!?"

Rath's comically stunned expression made G hold back a snort at the sight. "Destroy!? You really haven't heard of me!?" Rath slammed the watch symbol one more time, and then, the green light came and went. And in its absence, came a rather human looking dude. And in G's opinion, a really cute one, at that.

"I'm Ben Tennyson!" But even with that declaration, no one – aside from G – knew who the heck this dude was. At all. "Ben 10? Like … the biggest hero in the world?"

And right on cue, Alpha landed roughly atop a parked empty car a few feet behind them, scaring away the nearby citizens, as Six kept his grip on the menace on top.

"Six!"

Six brought his dual magnetic swords down and through the mech beast's chest before yelling out, "Everybody, down!" Right before blinding red lights of energy came out from the creature's core; the sharp brightness of it causing everyone to cover their eyes. Well, almost everyone.

"SIX!"

000

As Rex cried out, G made a gut decision.

Having already used the best of her abilities to teleport people out of harm's way from crashing vehicles and falling debris of buildings all caused by Alpha's terrifying stride across the city, she felt herself reaching her limit. But, after failing to warn Rath of Rex's landing from above attack earlier even though she'd knew he'd be alright, she felt she had to redeem herself. And this time, she just couldn't follow script on this one. Not knowing what consequences it would bring but not wanting to see Rex and his family to go through that pain either, she couldn't bring herself to let it be. Her mind was worn out, but her heart beat rapidly as she pushed herself, literally, past Ben and Rex, and towards the source.

Ben felt his heart give out as she blinked out in her signature glow, knowing what she was gonna do. Checking his watch, it was now red, which meant no hero time. Not this time. "G, NO!"

She teleported before them before reappearing out of thin air beside Six before tackling him, wrapping her arms around him as their joined forms fell off the metal beast; her form and eyes glowing an ethereal blue which made both guys gawk at the sight when both G and Six were caught in the red light.

Followed by a red energy wave that blew up from inside the metal creature. Inwards to outwards, a red energy bubble appeared and grew continuously; making the ground before them pull itself apart as rocks and dirt clouds followed, before that energy bubble popped and the resulting energy wave broke through all the glass windows in the area. As the red lights finally died down, everyone lowered their raised arms that shielded them from the blast. Rex immediately ran over to the two forms that were a few feet apart and away from the explosion sight.

The sight of Six. No sunglasses on to hide his pained expression, his green swat suit was ripped and torn in some places and burnt in other places, and his mouth slacked open as he was out cold. Seeing him like that, it made Rex's heart drop.

"Six! Hold on! Holiday, Six is down! Six is DOWN!" Rex informed her through his COMM as he carefully held Six, not wanting to hurt him even further and hoping Doc arrives as soon as possible when he looked over his shoulder to see Ben's green jacketed back as he was on his knees. The sight of that man caused Rex's vision become clouded with teary eyed hatred. "This is all YOUR fault!"

But as he blinked the tears back and Ben slowly turned around to look at him, Rex just then noticed the unconscious form of G held just as carefully in Ben's arms; one of them supporting her head while the other wrapped snug around her waist, and Rex felt his stomach almost lurch. G shielded Six the best she could from that explosion. So she took most of it; even though Six still got injured too. Her arms and hands had red burns and bleeding cuts from the glass shards on the ground, clothes torn and covered in gravel dirt as her top especially was smeared from the contact of the blood dripping down her skin; the heart in the shirt's center dyed in crimson. Her face was dusted in scuff marks and dirt as the side of her forehead was smeared in blood from the open wound she made when she crashed to the ground.

"My fault? It might as well be … since I didn't stop her. I couldn't do anything. Even so …" His shadowed eyes came to light, revealing his teary green eyes full of hatred for Rex. "This is just as much YOUR fault!"

"Like hell it is!" Rex roared back.

"You made the first blow! You thought I was the bad guy! And if I found her sooner instead of fighting with you, none of this would have happened!"

"You could have stopped her from running away, genius!"

"So could you, dumb-ass!"

"Why you – !" Rex was cut off by a soft, pained whisper.

"S – Stop." A weak grip on Ben's lower jacket sleeve made him stop too as both guys diverted their attention to the barely conscious G as her eyes struggled open, trained on Ben's face. "T – This is so off script." She murmured.

"You idiot. What the hell were you thinking, huh?" Ben tried to keep his firm glare in place, but the longer he stared at G's hazy eyes and her damaged form, the more his anger got muddled by his grief. "Goddammit, G. Why?" He sat back on his calves as his left arm moved underneath her thighs while his right arm wrapped around her lower back before slowly pulling her atop his lap, having her curl up against his front. He didn't care if he got himself covered in dirt and blood. His desperate need to keep her as close to him as possible without hurting her further was eating him up inside.

She laid her head against his chest; feeling so light-headed, as her eyes traveled to Six. "I … I thought I could save him. Is he …?"

"Out cold. It's bad." Rex's face crumpled as he looked down at his partner, already picturing G's own torn up expression.

"Please don't talk. You need to preserve your strength. Just keep your eyes open." He gently ordered, kissing her faded scar at the top of her forehead.

As Rex watched the pair's interactions, his mind started wandering to something G told him in Doc's room. If Rex ever met her boyfriend, he would get his ass whooped. She was getting all cuddly and friendly with this Ben dude's cat form earlier before too. Ben held her like she's the most fragile, precious thing ever … like she's his whole world. The pieces began to fit.

"You're … G's boyfriend."

Rex spotted his team's ship coming in the distance towards them as Ben's teary eyed glare met his own. "I am."

A/N: I was in the mood to finish writing most of this.

SO! Technically, Ben is 16 while Rex is a year younger but is 5 ft 8 inch while Rex is 5 ft 11 inch, canon info~!

BUT! In this AU of mine, Ben is 18 and 5 ft 11 in, Rex is 17 and over 6 ft, G is 16+ or at least close to being 17 and 5 ft 10 inch like moi. Moi likes taller bois than myself but sometimes shorter bois are fine too.

ANYWAY! I hope you enjoyed ... whoever reads this.

Until next time, bye bye~!