Union academy and Verse academy, two well known hero schools with extremely different teaching styles.

Union is known for their traditional hero views of saving people and putting villains in jail. Many heroes such as All Might and Team STRQ graduated from here. Most, if not all, Union students and supporters sees Verse as no better villains for killing villains.

Verse on the other hand are more brutal with their views. They save people like Union, but kill some villains such as Joker. One weird thing about them however is that they actually try to rehabilitate some villains who were victims of circumstance.

Right now, Ozpin, Nezu, and Sirzechs, who are the Union Headmasters, are speaking to Raiden (Mortal Kombat), Biblia (Trinity Seven), and Integra Fairbrook Wingates Hellsing. Said meeting between them is being broadcasted to not only their respective schools, but the entire world.

Nezu: And that's why you should reconsider your teaching styles and allow your students to attend Union. 

Integra: I'd rather teach Alucard to act like a normal person and be kind to others.

Raiden: We do not teach our students to be mindless killers, just that killing is sometime necessary.

Biblia: Besides, our students have nothing to learn from you. Frankly, they're stronger than Union students, especially our strongest student, Antithesis, as he was nicknamed.

Sirzechs: That's where your wrong. Our star student, Ren 10, can defeat any Verse student.

Integra: How about this, Ren 10 vs Antithesis. If we win, you must give us that extraterrestrial sword you found. If you win, we will send our best teachers to train your students.

All 6 headmasters shake hands and the scene changes to the dorm building of Union. There, we see a Caucasian male with brown hair and green eyes. His attire consists of a black shirt, blue jeans, a green jacket with white stripes on his left sleeve and the number 10 on the right, and white and black Converse shoes. This is Ren Tennyson, son of Julie Yamamoto and Benjamin Tennyson AKA "Ben 10K". 

Currently, he's sitting with Class 1-A, the ORC, Team Rwby, and Team JNPR. Most males see him as a lucky guy because he's in a relationship with Ruby Rose and Asia Argento.

Kirishima: I can't wait to see this fight!

Jaune: Me neither. 

Ren: Come on guys, it's not that big of a deal.

Weiss: Of course it is you dolt! A fight between Union's strongest and Verse's strongest will be a duel of the century.

Pyrrha: It would be nice to see the strongest students from each school to battle.

Bakugo: As much as I hate to admit, Ren's gonna win this.

Everyone agrees with the explosive student. At Verse however, the reactions are different.

Raiden (MGR): I thought they wanted a fight, not a slaughter.

Dante (Young): Eh, we all know Y/N's gonna win. 

Dante looks at Y/N, who's laying on one of the couches. Y/N is a dark skinned male with black hair with red tips, red eye markings, and abnormally sharp teeth. His outfit is an incredibly intense one that gives you demon vibes.
(Remove the hollow mask and change the markings and hair tips from blue to red)

Outfit

Y/N: Hell yeah, why would I lose to some pussy from Union?

Y/N on the other hand is known throughout Verse for his brutal style. He however is well liked by other students and is also seen as lucky, but that's because of his powers. He's also friends with one of the most attractive girls at Verse, Loba.

Loba slaps Y/N on the back before laughing.

Loba: Don't get so worried, we know you'll wipe the floor with him.

The scene changes to where both boys are looking out of the window and everyone looks at them with worry.

Y/N/Ren: That ain't/isn't why I'm worried. I'm worried cause his dad/mom will be there.

Dante/Bakugo: What's wrong with that? I'm pretty sure any dad/mom who lets his/her kid go to Union/Verse is soft/stupid.

Y/N/Ren: Ren/Y/N is my pussy ass/brutal and justice dick riding/non caring half brother.

Timeskip
It's the day of the tournament and the arena is filled with cheering enthusiasts of Union and Verse. Many are excited to see how a fight like this will turn out. People even came out to support each school by wearing the colors favored by the fighters. Green and White for Ren, and Black and Red for Y/N. In the spectator's box, the headmasters, Optimums Prime, Princess Celestia, and Princess Luna are all waiting for the battle. Suddenly, the doors to the spectator box opens and their 5 special guests walk through.
Ben 10K and Julie Yamamoto, the parents of Ren Tennyson (Couldn't find a picture of adult Julie so use your imagination)

Gwendolyn Tennyson, a Human-Anodite magic caster (Her and Ben aren't blood related)

Kevin Levin, the Osmosian friend of Ben and Gwen

Ingrid Axford, the mother of Y/N Axford

All 5 guests sit down with Julie and Ben sitting away from Ingrid. 

Ben: H-hey In-

Ingrid: Shut it fuck boy, unless it's an apology for what you did.

Five more people enter the box and everyone looks to see Looma Red Wind, Gar Red Wind, Princess Attea, Azmuth, and Tetrax Shard. As soon as they sit down, they pay attention to the arena where Present Mic is announcing the fighters.

Present Mic: ARE YOU READY TO WATCH A CLASH BETWEEN TITANS?!?

Everyone cheers as Present Mic starts speaking again, albeit with more enthusiasm as he's excited for the fight as well. He turns everyone's attention to the right side of the arena. The doors open and Ren walks out with a Blue tracksuit with the letters "U" and "A" on it, which stands for Union Academy. (Basically the Mha gym uniforms)

Present Mic: IN THE RIGHT CORNER, WEIGHING 190 POUNDS AND A HEIGHT OF 6'2, HE'S THE SON OF THE FAMED BEN 10K, WE HAVE REN TENNYSON!

Everyone cheers for the son of the famed hero. Ren blushes in embarrassment but smiles and waves back. His sleeves however are rolled up to reveal his Omnitrix.

Present Mic: AND IN THE LEFT CORNER, WEIGHING 235 POUNDS AND A HEIGHT OF 6'7 INCHES, HE'S THE SON OF THE SCARIEST WOMAN IN THE WORLD, POSSIBLY THE ENTIRE SOLAR SYSTEM, WE HAVE Y/N AXFORD!

Everyone looks at Y/N walking to the arena from the left side door. His outfit is drastically different as Verse doesn't have any uniforms. He's wearing black combat boots, camouflage pants colored black, white, and gunmetal gray, and a black tank top. Not many people cheer for him apart for the Red Winds because he looks like a strong and menacing warrior, his mother because she wants to see blood, and the Verse supporters as well as the Verse students and staff. Ren, Azmuth, Tetrax, and Ben's eyes widen as they see what's on his wrist.

(Remove the pipes)

Ben: How did he get an Omnitrix?

Ingrid: He doesn't have an Omnitrix dumbass, his is basically a more badass version of it.

Tetrax: How so, Ingrid the Bloody?

Ingrid: You'll see.

Present Mic: THANKS TO SUPPORT FROM SORCERESS (Gwen), PRINCESS LUNA, AND PRINCESS CELESTIA, THE LANDSCAPE WILL CHANGE RANDOMLY TO TEST OUR FIGHTER'S ADAPTABILITY AND SKILL!

Present Mic lays down the rules and regulations of the fight. Simple stuff really, only rule is that they can only fight with what they have and can't have outside help from anyone. Both boys nod and he quickly leaves to avoid being collateral damage. As soon as the buzzer rings, Ren wastes no time in picking an alien from the Omnitrix. He decides to go for an old classic.

Ren: HUMUNGOUSAUR!!!

Y/N retaliates with his own form. It looks similar to Humungousaur, but red in color with digitigrade legs, a lizard-like tail gold armor on its shoulders and arms, and a head similar to theropod dinosaur.

Y/N: HUMUNGORAPTOR!!! 

Humungousaur: WHAT THE-HOW?!

Humungoraptor wastes no time and tackles Humungousaur before wailing on him without mercy. Despite being skinnier than Humungousaur, Humungoraptor is stronger than the aforementioned Vaxasaurian. Humungousaur manages to kick Humungoraptor off of him and attempts to slam his hands down on the red Vaxasaurian. Humungoraptor merely smirks and shoots a beam of red energy at Humungousaur, knocking him back. Humungousaur is quick enough to get up and box Humungoraptor, but Humungoraptor's superior hand to hand skill and physiology allows him to keep up with and overpower Humungousaur. Humungoraptor grabs Humungousaur by the tail and slams him to the ground a couple of times before throwing him. Suddenly, the landscape changes from the arena to a volcanic like area. Ren changes from Humungousaur to a fire alien he loves to use.

Ren: HEATBLAST!

Y/N chuckles before changing into his version.

Y/N: HOT SHOT!

Before Heatblast can say anything, Hot Shot bombards him with a flurry of fireballs. Like Humungoraptor and Humungousaur, Hot Shot is stronger than Heatblast. Both fire aliens get into a solid stance before charging orbs of fire into their hands. At the same time, they shoot beams of intense flames at each other. Hot Shot's dark orange beam quickly overpowers Heatblast's yellowish white flames. The latter is sent flying back, making Hot Shot laugh.

Hot Shot: Anything you can do, I can do better! This is the power of the Antitrix, mutation!

Suddenly, the landscape changes to a sky. The flaming aliens quickly fall and choose new forms suited for flight. 

Ren: Big Chill!

Ren slaps the dial on his chest, making his form gain a fire like color scheme. 

Ren: Ultimate Big Chill!

Ren quickly maneuvers to freeze Hot Shot, but the latter does the same process as Big Chill and becomes a more feral looking version.

Y/N: ULTIMATE FROST BITE!

Frost Bite: GO AHEAD, USE ANOTHER FORM! ANYTHING YOU HAVE, I HAVE A SUPERIOR VERSION!

Ult. Frost Bite shoots a beam of ice-electricity from his antennas, which is countered by Ult. Big Chill's fire-ice breath. Both evolved ice moth aliens engage in aerial combat with Ult. Frost Bite causing more damage than Ult. Big Chill due to his size and ferocity. Ult. Frost Bite manages to scratch Ult. Big Chill's upper and lower left wings, causing him to spiral out of control. Grinning, the larger alien swoops and bites down on Ult. Big Chill. Luckily, the landscape changes again, allowing Ult. Frost Bite to throw Ult. Big Chill against one of the trees. Said landscape appears to be a forest with large trees littering the entire area. The trees are far enough apart to where someone with superior agility can traverse the treetops easily but close enough to offer cover for stealth based fighters. Ult. Big Chill flies into a tree to catch a breather while Ult. Frost Bite relaxes for a bit. Ult. Big Chill turns back into a heavily breathing Ren.

Ren: How is he so strong?

Ren notices a shadow look over him and looks up. He sees Ult. Frost Bite flying over him and covers his mouth as to not make a sound. Ult. Frost Moth looks around for Ult. Big Chill before shrugging and perching on a nearby branch. Said branch is strong enough to support the large alien, who sighs in contempt and basks in the sun despite being a cryokinetic insect alien. Ren manages to quietly sneak away and hide in a denser part of the forest.

Ren: It's like he's toying with me. He isn't even fighting seriously, he's playing with me like a cat who's hunting a mouse.

???: What's the point in going all out on something so weak and worthless?

Ren jumps back in shock at Y/N, who was hanging upside down behind him. Ren slams his Omnitrix and turns into a rooster like alien with elbow blades.

Ren: KICKIN HAWK!

(Ren's Kickin Hawk looks just like Lian from Omniverse with the Omnitrix logo on his chest)

Y/N shakes his head before landing from the branch and changes into his version of Kickin Hawk. 

Y/N: FALKWONDO!

Timeskip
It's been 45 minutes since the match started. Ren, who is in his Four Arms form, is on a knee breathing heavily in the normal arena as it changed back to that, albeit temporarily. Every alien Ren used, Y/N used a better version of it. Even the aliens he and his dad hate using get outshined by Y/N. Luckily, the Antitrix has a charging period like the Omnitrix, but Y/N mimicked the properties of concrete from the arena. This is because he's half Osmosian, courtesy of his mother. Y/N fought Four Arms on equal terms thanks to his brutality and got the Tetramand on one knee.

Four Arms: How are you so strong?!

Y/N: It's because I have good genes from my mom and not that limp dick fuck boy you call a dad.

Y/N delivers an uppercut to Four Arms, knocking him onto his back.

Y/N: I want you to know something pipsqueak. No matter how much you train, no matter how many people you beat, no matter what aliens you get, I will ALWAYS be better than you. You're just a wimp who rides the dick of justice.

Something snaps in Four Arms. Y/N has done nothing but berate and humiliate him this entire fight. He even openly admitted Ren's too weak for him to go all out on. Four Arms stands up and looks at Y/N with a hardened and rage filled glare.

Four Arms: WELL AT LEAST MY DAD DIDN'T LEAVE ME!

-With the guests-
Julie and Ben gasp at what their son said. While it is true, it's not something to take lightly. Julie looks at Ingrid with a sympathetic look.

Julie: I am so sorry-

Ingrid just drinks from a bottle of Vodka and watches the match.

Ingrid: I should be the one apologizing, but I won't.

Ben: For what?

Everyone notices a shadow cast over Y/N's eyes. The students and some supporters of Union laugh and berate Y/N on being abandoned. Everyone notices the Headmasters say nothing and look at Y/N with a slightly mocking look. Looma, Gar, Attea, and the princesses look as if they're going to say something, but Ingrid stops them.

Gar: You're going to sit there and let your own flesh and blood be insulted like that?!

Ingrid: Y/N is gonna beat that kid's ass to kingdom come, so what's the point?

3rd pov
The landscape changes to a dark room with concrete pillars, giving a backrooms type of feeling. Four Arms looks at Y/N in horror as to what he said.

Four Arms: Y-Y/N, i-

Y/N: Shut the fuck up you spineless pussy! 

Y/N smirks sadistically as Ren times out.

Y/N: Since you think it's funny to insult me about not having a dad-

Y/N changes into a wolf like form before roaring directly in Ren's face.

Y/N: I'M GONNA BASH YOU RIGHT IN THE FUCKING MOUTH!!! 

Bashmouth uses his metal teeth to grab Ren buy the arm and throw him around like a toy. Ren screams in anguish as Bashmouth treats him like a chew toy. When Bashmouth throws Ren, the green male uses this chance to run away with Bashmouth hot on his tail. Ren tries to use the concrete pillars to his advantage, but Bashmouth makes quick work of those thanks to his natural metal plates. The arena changes one final time to a wide open space with nothing but solid ground as far as the eye can see. Ren notices Y/N change back to normal, and takes a breather.

Y/N: The hell are you so relaxed for? I'm done holding back just like you wanted.

Y/N slams the dial on his Antitrix before transforming into his strongest alien.

Y/N: DEVASTATOR!!

Ren quickly changes into his To'kustar form to fight on equal terms with Y/N. 

Ren: WAY B-

Devastator decks Way Big in the face before he could finish his entrance. There is a noticeable height difference between the two as Way Big is 100 feet while Devastator reaches to 120. Way Big constantly swings at Devastator, but the Mutant To'kustar keeps evading every strike. Devastator delivers a jab at Way Big, which lands its mark. This allows Devastator to wail on Way Big with punches ranging from jabs to hooks. Devastator sends Way Big flying with a jab, but Way Big quickly recovers and punches Devastator in the stomach. Devastator however ignores the hit and punches Way Big with three consecutive punches before finishing with a uppercut.

Devastator: 3 piece and a biscuit!

Devastator knees Way Big and picks him up before throwing him against the ground. Way Big gets up and punches Devastator, but the latter catches it before moving under Way Big and kicking him in the back. Way Big tries to deliver several punches but Devastator slaps all of them away with ease. Way Big goes for a kick, but Devastator merely throws him a considerable distance. Way Big springs up and gets into a stance.

Devastator: Guess that was on me. Oh well, do your worst. 

Way Big crosses his arms and shoots a green beam of energy at Devastator. Devastator retaliates and shoots his own red beam to counter the green one. Both beams clash together with neither one gaining any advantage.

Way Big: Y/N, I'm sorry for what I said to you!

Devastator: You're still talking? Guess I need to stop holding back on this beam.

Way Big's eyes widen as Devastator's beam doubles in size. This is due to Devastator's arms possessing two fins instead of one, allowing him to use beams twice as strong as a normal To'kustar. Way Big gets sent flying, so Devastator uses his enhanced speed to grab Way Big by the head fin, as it's a To'kustar weak spot, and drag him through the ground while running. After doing this for quite some time, Devastator throws Way Big aside and sees that he carved his name in the land. The landscape goes back to the arena just as the boys transform back into their human forms. Y/N quickly changes into a form that scares not only Ren and Ben, but Gwen, Kevin, Optimus, the Headmasters, the Red Winds, Attea, and Tetrax.

Y/N: TENTACTHULHU!

-With the guests-
Shock is all they can express. Not only has Y/N gotten superior forms of all of Ren's aliens, but he also has a superior form of Ben 10K's strongest and most dangerous villain, Vilgax. They hear a sniffle and see Ingrid crying tears of joy.

Ingrid: I remember when he got that form.

Looma: How? 

Ingrid noticed how Looma and Attea looked at Y/N when he used Quad Smack and Battle Toad, and is going to tease her son about it later.

Ozpin: I would like to know as well, a boy his age should not be near someone like Vilgax.

Ingrid: Way to ruin the mood. Well, princesses, he gave me Vilgax's arm as a Mother's Day gift when he was 10, and it's been on my wall ever since.

Gar: Such an impressive feat for a mere child to accomplish. 

3rd pov
Tentacthulhu grabs Ren and lifts him up as his eyes glow red. An alarm rings out however, making him look annoyed. That buzzer signals that the match's time is up. The timer was put in place in case the match went on for an extended period of time.

Present Mic: AND THAT'S THE TIME FOLKS! OUR WINNER........ Y/N AXFORD OF VERSE ACADEMY! LET'S GIVE HIM A BIG ROUND OF APPLAUSE FOLKS!

Y/N changed back to normal and dropped Ren, allowing medical bots to take him to the infirmary. Every Union teacher (almost), supporter, and student booed Y/N until he walked out of the arena. Did he care? Not in the slightest. His mother comes out of nowhere and wraps an arm around her son's shoulder while smirking.

Ingrid: Great job Feral, that fight was amazing despite it being one sided!

Y/N: Thanks mom. I don't know why people are getting their panties in a twist when villains are gonna do the same thing. 

Ingrid: Not to mention you got two women wetter than the ocean for you.

Y/N: Huh?

Y/N feels himself get picked up and hugged from behind by four muscular arms. He manages to get out of the hold and looks at the culprit, only to be scaroused.

Attea: Come along husband.

Loona: Let us engage in brutal forepummeling!

Y/N: You mean sensual foreplay right?

Looma:.....

Y/N: Right?!

Ingrid: Have fun son, I'm going to a bar to get sloppy drunk. At least, I'll try since my tolerance is higher than a fucking kite.

Ingrid gave her future daughters in law her address and they brought Y/N to the house. 

And he was never seen again.

Kidding, he's the protagonist