Japan: Morning…

Rex Salazar was a middle school boy of Hispanic heritage with lightly spiked, slicked back dark hair. He was currently dressed in his school's beige uniform as he was coming back from a long day. He sighed as his teacher's words echoed through his mind.

"I know many of you wish to enter the Hero track, but some Quirks are better suited to other fields. This aptitude test I'm handing out should help you determine that. Don't stress about finishing them since you may take it home and bring it back tomorrow."

Rex lifted the blank aptitude test to look at it. High school entrance exams were coming and part of him knew he wouldn't enter his school of choice, UA.

"What does he know!?" He gripped the paper in frustration. "I'll show them what I'm made of once I'm a Hero!"

Rex heard it all his life. People always said his Quirk was impressive, yet it'd be wasted in the Hero course. He had small, biomechanical machines in his body that gave him a healing factor, durability, and , people said he'd be useful as a Hero, no one ever denied that.

Then, they were always quick to bring up what he couldn't do well. He couldn't stop fires, beat 10-foot-tall villains, save people from earthquakes, and so on. Everyone always told him he should just go into the support field like his parents and brother.

His Quirk and intelligence made him perfect for it. While he had no problems with anything support related, it angered him on how people shot down his dream. In the end, all he could do was lie to himself and say he would show them.

Deep down, he knew it wasn't true. Rex had always wanted to be a Hero, even become the next top Hero of Japan, but his Quirk simply wasn't on par with whatever All Might had. Even if he didn't want to admit it, he knew people were right in that it was a perfect Quirk for support.

Even with all that, he hoped one day something would change. Rex soon made it down to the subway and entered the one that would take him home. The guy plopped down into a seat and stared at the aptitude test once more thinking on what his future could be.

Salazar Home: Evening…

Rex sighed in relief, glad to be home, as he opened the door. "Hey I'm…"

He froze and his eyes widened upon what he saw. His brother and mother were restrained by vines while his father was passed out on the floor with a man's boot on his back.

"Rex, save yourself and get help!" Caesar, Rex's brother, yelled.

"Leave him out of this Van Kleiss!" Violeta, Rex's mother, yelled. "He has nothing to do with this!"

Before Rex could react, he was ensnared by vines just like his mother and brother.

Van Kleiss smirked. "Well now, excluding one of the family simply wouldn't be fair." All three Salazars struggled against their restraints with no luck. "Maybe he will be more reasonable, or he could help me get what I want from the rest of you."

To accentuate that last point, vines tightened around Rex causing him to scream in pain.

"Stop, we'll give you what you want." Violeta declared. "Just leave him alone!"

"Mom, no!" Caesar yelled.

Vines quickly moved to cover his mouth while they lessened around Rex just enough to keep him restrained.

"Caesar, you are just entering adult hood, so I believe you should leave the talking to your elders." Van Kleiss informed as he approached Violeta.

Rex was panting while feeling pathetic. A villain had taken his family hostage, and he was simply a bargaining chip. It made him feel like an idiot for thinking he could ever be a Hero. For as long as he could remember, he had an idea of what Hero he could be with his Quirk.

He aspired to be like All Might; however, he'd do it in his own way as a Hero that fought with tech. In his free time, he'd even sketched out various things he'd create with his present favorite being an idea for a pair of giant metal hands. He called them Smack Hands.

He wished he had them right now to break free, save his family, and knock Van Kleiss' smug look off his face. Seeing that smug, self-satisfied look, coupled with the present situation, made Rex furious. With these strong emotions raging, his nanites started to react.

They were changing from yellow, like his father's and brother's, to a blue color. Glowing blue panel lines ran along Rex's arms before gray metal fibers formed around them. Then, two giant orange gauntlets formed out of the metal fiber.

They broke through the vines, shocking everyone in the room. Rex himself was shocked, but he had no time to question it. He instead ran forward swinging his left smack hand at Van Kleiss punching him through a wall. His grip on the rest weakened.

"Since when could you do that mi hijo!?" Violeta asked, shocked.

"Since about like five seconds ago." Rex answered.

Van Kleiss got up from the rubbed and dusted himself off. "Well, this is an interesting development." He was annoyed. "One which I don't wish to deal with at present." A crimson red portal opened behind him. "I do apologize, but I must take my leave."

Van Kleiss started to move through the portal prompting Rex to try and stop him. "No, you don't!" Unfortiunately, he was too slow, and Van Kleiss escaped. "Gah, great I let him get away!"

Rex's metal fists broke down into piles of scrap metal.

Cesar approached and put an arm around his little brother's shoulder. "Hey, don't beat yourself up over it, mi hermano. What matters is that you managed to drive him off."

"Que paso?" Ask a dazed Rafael as he came to.

"Van Kleiss happened." Caeser responded.

"Who even was that guy?" Rex asked.

"An employee who resigned a week ago after an argument with dad." Ceasar responded. "I'm guessing he then went to the black-market side of support items."

"Knowing that man, wouldn't surprise me if he was always part of it." Violeta took out her cell phone to call the cops. "He always was shady, even as our employee."

She walked away to make the call.

"Still, how did he get through the house's defenses?" Rex asked.

"I don't know, but we'll begin an investigation." Rafael voiced. "We'll likely be moving as well."

"Anyways, what were those giant fists you made, mi hermano?" Caesar asked.

"Honestly, no clue." Rex shrugged. "I just wanted to save you all and punch Van Kleiss' smug look off his face."

"We can figure that out later." Violeta voiced as she rejoined them. "I just called the cops, and they will be here shortly."

The police and some local Heroes ended up arriving. While the police surrounded the home and got statements, the Heroes took off to patrol in case the villain came back. Once the Salazars gave their statements, they left for a hotel.

Generator Industries: Next Morning…

Violeta, Rafael, and Caesar went to work at their company after ensuring the local Heroes were notified to patrol around the hotel where Rex was. Their company, Generator Industries, naturally dealt in Hero support.

Their largest contract was Japan's sixth Hero, Six, who had started the Providence Hero Agency. Given the sheer number of people who worked with him, it was a lucrative contract. Right now, they were in Rafael's office looking over Van Kleiss' work to see how he breeched their systems.

Caser found something within his resignation email. "I see, he must have been planning this all along."

"What did you discover, mi hijo?" Violeta asked.

"His resignation email has his code all over it." Caser informed. "The moment it was opened, that code dug into our systems letting him deactivate our security."

"That snake." Rafael declared. "This time, all three of us will work to create a security system he couldn't hope to penetrate like the last. Given our home's current state, and the need to work on the system, it'll be easier to simply move."

"I wonder how Rex is going to take it?" Violeta asked.

"Depends, are we moving close to UA?" Caesar asked.

"You're not suggesting he's going to try for UA?" Violeta asked concerned.

"Honey, I know you are always worried about our boys, but Rex is growing up." Rafael stated. "Hey, if we help him master his new ability, he will do great."

"I know we need to let him spread his wings, but Hero work is dangerous." Violeta sighed. "At this point, nothing will stop him. Even if we try, he's likely to disobey and go for it anyways."

"That's why we should support rather than fight him on this." Caser stated. "He'll be better prepared with our help."

Forest: Night…

Rex snuck off to a nearby forest where he was attempting to make his Smack Hands again, but any time he made them now, they'd simply crumble to scrap metal.

"Why can't I get this right!?" Rex yelled frustrated.

"Could be a design issue since you did design them when you were five." Caesar commented as he came up behind his little brother startling him.

"Dude, what did I say about sneaking up on me like that!?" Rex exclaimed annoyed.

Caesar crossed his arms. "In response, I said you needed better senses."

"I know." Rex sighed as he sat on the ground. "I just want to figure out this new ability."

"Let me guess, you hope to use them to make it into the Hero course?" Caesar asked.

"Did mom send you to stop me?" Rex asked. "No matter what any of you try, I'm going to make it in one way or the other." He looked at his hands. "I finally have the thing everyone said I was missing to make it, so…"

"Easy, mi hermano." Caeser interrupted with a smile. "We already realized that there's no stopping you, so we're going to offer our support. Make sure you do things right rather than risk something going wrong because you weren't prepared."

"Alright!" Rex smiled as he stood. "Where/when do we start?"

Caesar took out a book on robotic and mechanical engineering. "Right now." He passed it over to his brother. "Honestly, it was a miracle the smack hands you made even lasted for a punch."

That bruised Rex's ego a bit. "Hey, that poor design saved your butt!"

"I know hermano." Caesar nodded before moving on. "Now, let's go over your schedule for the next 11 months. During this time, mom's going to be wiping up the best meals to compliment your workout routine and ensure your metabolism is well taken care of.

From what we've determined, your builds seem to eat away at that. Speaking of your routine, you're about to be working harder and more than you ever have before. Additionally, we'll be working on your engineering, robotics, and programing.

The stronger your mind and body, the stronger your builds should be. That is your Monday through Friday schedule. Saturday and Sunday will be your day to rest as your body acclimates to the changes of the prior week."

"Alright, I got it." Rex smiled. "Workout and learn to make even better Smack Hands that I can use to beat down the bad guys."

"Not only for that." Caesar informed. "I believe you simply need to open your mind to the possibilities, and you'll be able to make pretty much anything from that notebook of yours."

"That sounds great." Rex declared.

"If you want to get to that point, we got to start from the basics." Caesar declared. "I hope you're ready because I'm not about to go easy."

Rex opened the book. "I would expect no less."

Rex was prepared to not only succeed but surpass his family's expectations. The change he wanted had arrived, so his whole being was now committed completely to his goal. He would work to achieve it and prove his family's belief in him the right call.

Generator Industries: Next Morning…

Rafael and Violeta had taken on most of Caesar's work within the company to ensure he could be there to help Rex. Right now, the Salazar parents were at their office working on designs for new support items. That's when a large, muscular man burst into the room.

He had short, blond hair swept backwards and with two distinct tufts that stuck up above his head. This man is known as the Symbol of Peace and Japan's number one Hero, Toshinori Yagi. Also known as All Might.

He gave a boisterous laugh. "I am here to check in on my friends!"

Rafeal sighed as Violeta giggled. "You know mi amigo, when we said you were free to drop by, we were hoping you'd at least knock."

"Sorry, but I wanted to check in on how the Salazar family was doing." All Might rubbed the back of his neck truly concerned. "I had heard of the villain attack and hopped everything was alright."

"We appreciate the concern, but we came out alright." Rafael nodded to a couch. "That said, you are here so let's catch up."

All Might nodded and took a seat while Rafael and Violeta saved their current work. Rafael then sat on the couch across from the man while Violeta moved to make some tea.

"So, there were no injuries to any of you?" All Might asked.

"Nothing major." Rafael assured. "I did have a concussion while my hijos had bruising from the vines. Of course, we three have healing and durability, so small damages like that wouldn't last long. Even though Violeta lacks that, Van Kleiss didn't hurt her."

All Might sighed in relief as Violeta put three teacups on the coffee table, between the two couches, before sitting next to her husband. "With that out of the way, I've heard you're going to teach at UA. Does this mean you still haven't found a successor?"

"Actually, I have." All Might broke out in a large grin. "He's a Quirkless boy who seems to be a bit of a crybaby, but he's got the heart of a Hero. All he needs is the training for the entrance exam which is something I have started him on."

"That is good to hear." Violeta nodded. "Maybe he'll be a classmate with our youngest hijo."

"Ah, young Salazar is trying out for UA?" All Might asked interested.

"Yes, he discovered a facet of his Quirk that allows him to build machines." Rafael spoke with pride. "In fact, it was this new ability that saw him driving off the villain."

"Well, I can't wait to teach him." All Might laughed. "I've always thought he had the heart of a Hero; however, his fluctuating drive made me hesitant in choosing him. It seems now that is no longer a problem; however, I have already cemented my choice in young Midoriya."

Had he not met his current successor, All Might knew hearing this would have cemented young Salazar for the role. As things stood, he knew Rex would become a fine Hero.

Rex's Training

Rex was put through the mental/physical training from hell, especially with the weighted bracelets and shin guards he was told to wear every day. One day, Rex would be learning about mechanical things, like pistons and gears.

The next would see him run miles as a warm up before doing pushups, pull ups, sit ups, and countless other upper body exercises. The other would see him doing back squats, leg presses, and many more lower body workouts. While doing all this, Rex still went to school.

There he applied himself fully to earn the best marks he could. On rest days, Rex would work on his Smack Hands along with a whole slew of other ideas he had. These included: Boogie Pack, Slam Canon, Rex Ride, Punk Busters, and Big Fat Sword(B.F.S).

In the early days of training, they'd crumble into scrap metal, short circuit, and/or explode. While Caesar did obviously teach Rex, he refused to help him with these designs. He felt it was best his little brother made mistakes to learn from them.

Backyard: 10 Months In…

With one month left until the entrance exam, Rex finally succeeded in making every one of his builds. All six functioned exactly as they should and weren't falling apart like his Smack Hands had after Van Kleiss left.

"Muy bueno." Caesar clapped before grabbing a tablet off the nearby table and approaching. "You managed to finish a whole two weeks before I projected leaving us plenty of time to complete your preparations."

"What do you mean?" Rex looked at his older brother in confusion. "With my builds, I'll dominate the exam."

"I'll admit, they are impressive, but there's one element missing before you're truly ready." Caesar messed with the tablet which summoned battle robots that surrounded the younger Salazar. "You got to know how to use them."

Rex smirked. "Alright, bring it!"

Rex ran forward building his smack hands and smashing them down on a robot. This kicked up dust which got in his eyes.

Gah, I can't see!" Rex yelled.

One of the droids fired rubber bullets which knocked him flat on his back.

"Oh boy." Caesar shook his head. "Well, it's a good thing we have a month now because this is going to be harder than I thought."

One Month of Training…

Rex's upper and lower body days remained, but his prior mental days were replaced with combat training. He utilized his various builds to fight the robots. Through this, coupled with his priorly gained knowledge, he managed to refine several of his builds.

He could now spin his Smack Hands using them to drill into the enemy or ground. His Boogie Pack now had grappling hooks, and the turbines could be fired off like a bola. His Rex Ride had a retractable battering ram. His B.F.S had a Battle Saw mode as well.

Beyond those upgrades, he began to understand how to utilize each build in combat. No matter how many times he was hit with oil, dust, mud, and other things, which got in his eyes, he would get back up to keep pushing himself.

Salazar Residence: Entrance Exam Day…

Rex's phone alarm began to go off prompting him to slowly open his eyes. "Why is my alarm going off so early today?" He checked his phone only to snap wide awake upon noticing what day it was. "It's entrance exam day!"

He quickly lept out of bed and got moving. While their son was getting ready, Violeta and Rafeal were cooking their youngest's favorite breakfast. It was huevo y salchichas, pancakes, and pan dulce,

"So, how well do you see him doing?" Violeta asked worriedly as she scrambled the eggs and added the sausage.

"Even without his builds, he'd have crushed them." Rafael was making the pancakes. "Our boy is smart, and the physical portion is made for what his Quirk was as its against robots. With all the studying and training he's done; I don't think anyone there will stand a chance."

Rafeal's words did make her smile before Caesar walked into the kitchen yawning. "Morning mami. Morning papi."

"Good morning, dear." Violeta greeted.

As Caesar too ka seat, his mother brought him a plate. "Made hermano's favorite, so he's not nervous?"

"Si." Violeta nodded. "I also want to ensure he has all the energy he needs to utilize his Quirk."

"You spent all this time training him." Rafael commented as he and wis wife brought over three more plates of breakfast. "Got anything to say about his chances today?"

"If anything, I'd say we overprepared for today, but that's fine." Caesar shrugged. "It just means he's got an even better foundation for the Hero course to run with."

Rex came down wearing black pants with a circuit pattern, a shirt, with the top half being blue and the bottom half white, black boots, black gloves, and a red jacket.

Violeta whistled "There's our future pro."

"You know it mom and man does breakfast look good." Rex declared as he sat down to eat.

"Do you feel ready to crush the exam?" Rafael asked.

"You know it." Rex declared. "I didn't work hard all these months to do anything less."

"Good." Violeta nodded. "Now, eat up to ensure your metabolism is covered."

After Breakfast…

Rex slid the plate back and stood up. "Alright, I've got to get a move on."

"Wait hermano." Caesar stood up. "Before you go, I've got a little good luck charm for you."

He handed over a gift box which Rex opened only to pull out a pair of orange goggles.

"Awwww, I remember we gave those to you after your first experiment." Violeta declared fondly.

"Wait, these are your goggles from our parents?" Rex asked. "Why give them to me?"

"Well, today is important, so you deserve a little something." Caesar informed. "Considering there's bound to be plenty of dust, those should do the trick in protecting your eyes. I also took the liberty of modifying them with night vision, thermal vision, x ray, and a binocular mode."

"Coolest gift ever!" Rex put the goggles on top of his head before hugging his brother. "Thank you, hermano!" It wasn't long before they broke the hug. "Okay, I've got an exam to get to."

Rex hugged his mother and gave his father a fist bump before running out the door.

"So, what was the real reason?" Rafael asked.

"I never can get things past you papa." Caesar chuckled, "They were what helped me start on my journey with science and made me the man I am today. Now, they're going to help him start his Hero journey, make him a great man, and an even better Hero than All Might."

His parents smiled.

Rex Salazar

Quirk: Formerly Nanite; now Evo

He has durability, a minor healing factor, technopathy, and can build machinery from his body. Of course, the strength of his builds is determined by his own physique and understanding of engineering. The more he trains and studies, the better the machinery he creates. Addtionally, creating machinery takes energy which makes eating an important aspect of his life; otherwise, he cannot call on his builds.

This came about because I missed my prior My Hero crossover that got deleted, and I was getting anxious waiting for a new chapter of this story to come out from Justarandomdude56. Go read that if you want, it's three small chapters.