MHA: Reborn with Magneto's powers

After getting his parents' permission, Ryoma headed to the Yaoyorozu estate for the first time. The condition was simple—he had to return home before 6 PM. While Ryoma didn't think much of it, his mother was slightly amused that her usually reserved son was spending more time with Momo.

Upon arriving, Ryoma was greeted politely by Mr. and Mrs. Yaoyorozu, who welcomed him in. They were already familiar with his background and appreciated his presence in their daughter's life. However, they didn't hover for long, trusting Momo's judgment and giving them space.

Momo led Ryoma through the massive mansion, down a flight of stairs, and into an underground practice range. The space was enormous—reinforced walls, obstacle courses, combat dummies, even what looked like an area for live-fire exercises.

"This is what I wanted to show you," Momo said proudly, hands on her hips.

Ryoma's eyes widened as he slowly took in the sight. "This is… insane…"

Momo chuckled. "Wow, this is the first time I've seen you look so shocked."

Ryoma turned to her, still processing. "My wallet is having a heart attack. Miss 'Moneybags' over here has a whole secret training facility in her basement."

Momo pouted. "Hey! Don't call me that!"

A small soft plastic toy hammer suddenly formed in her hand, and before Ryoma could react—bonk!

"Ouch—!?" Ryoma clutched his head in exaggerated betrayal. "Did you just—?"

Momo smiled sweetly. "A lady defends her honor. Now, let's begin."

____________

First was Momo's turn.

Ryoma lifted several metallic objects into the air, sending them flying at different speeds and angles to mimic moving enemies. The challenge was to see how quickly Momo could react, create weapons, and destroy them—just like she would have to in the real exam.

Momo concentrated. Her skin glowed as she quickly generated a bo staff, spinning it in her hands before slamming it against an incoming projectile, knocking it aside. Next, she formed a shield, blocking another piece of metal Ryoma sent toward her.

"I need to be faster," Momo muttered, analyzing her movements. "If the robots come at me from multiple directions, I won't have time to think for too long."

"Try anticipating the attack before it comes," Ryoma suggested. "Your Quirk is creation-based, meaning you'll always have a delay. The faster you process the situation, the better."

Momo nodded. She switched tactics, creating smaller, faster weapons rather than large ones, prioritizing speed over power. This time, she successfully took down three targets before Ryoma sent another wave.

After several rounds, Momo was visibly exhausted. She walked over to a table stocked with prepared food, eating quickly to replenish her energy.

_____________

Next was Ryoma.

Momo, having studied the periodic table, began creating various types of metals for Ryoma to test his magnetism. She carefully arranged them into three categories:

Ferromagnetic Metals (strongly attracted to magnets): Iron, Cobalt, Nickel

Paramagnetic Metals (weakly attracted):Aluminum, Titanium, Magnesium

Diamagnetic Metals (repelled by magnetic fields) :Copper, Gold, Silver, Bismuth

As Ryoma focused on the metals Momo had created, he could feel the familiar pull of ferromagnetic and paramagnetic materials—iron, nickel, cobalt, and a few select alloys. They moved effortlessly under his control, twisting and flying around the training area with precision. However, the moment he tried to manipulate diamagnetic metals like copper, silver, or gold, nothing happened.

He sighed, crossing his arms.

'As expected… I'm still nowhere near that level yet.'

Momo, standing nearby, noticed his reaction. "Something wrong?"

Ryoma exhaled through his nose. "No, not really. I just confirmed what I already suspected—my power still has a long way to go. Right now, I can only manipulate ferromagnetic and paramagnetic metals. Anything diamagnetic is completely unaffected."

Momo tilted her head. "Well yeah, that's just how your quirk works right? Its limitations are the same as magnets, it can't work with non-magnetic things."

Ryoma smirked slightly. "That's what most people would assume, but in reality, magnetic fields can influence all matter—it just depends on how strong the field is."

Momo's eyes widened in disbelief. "All matter?"

Ryoma gestured vaguely to the air around them. "At a basic level, all atoms contain moving electrons, and electrons generate their own tiny magnetic fields. Most of the time, these fields cancel out, which is why some materials appear to be non-magnetic. But if a magnetic field is powerful enough, it can still affect them."

Momo listened intently, fascinated. "So even things that aren't normally magnetic—like copper, wood, plastic—could technically be influenced by magnetism?"

"Exactly," Ryoma nodded. "Under extreme conditions, even something as simple as water can be manipulated. Ah yes, let me show you this video."

Ryoma opened his phone to show Momo a video of scientists using a powerful magnetic field to levitate a frog on Youtube.

Momo not only had a small laugh watching how goofy the frog was when it floated uncontrollably inside the magnetic field but she also understood the unpredictable potential behind magnetism's power explained by Ryoma as well.

"Understand what I am trying to say?", Ryoma asked.

"Yeah…But wait,",Momo crossed her arms, thinking. "So… if you keep developing your Quirk, you might eventually be able to control anything? Even….living things."

Ryoma didn't answer immediately. He looked at his hand, flexing his fingers as if considering the weight of that possibility. "…Maybe. But that's far beyond what I can do now. Right now, I'm barely scratching the surface."

Momo was quiet for a moment. She had been excited at first, fascinated by the potential of Ryoma's abilities. But the more she thought about it, the more a strange unease crept in.

She hesitated before speaking again. "Ryoma… if your Quirk really can grow that strong, doesn't that mean it could become… incredibly dangerous?"

Ryoma glanced at her, reading the subtle concern in her expression. He had seen that look before—the doctor who checked his quirk's manifestation as a kid. He had certain knowledge of physics and was able to realize just how big of a threat his Quirk could become.

"It depends on how it's used," he said simply. "Like any tool, magnetism isn't good or evil on its own. But if my Quirk reaches that level, it could be weaponized in ways most people can't imagine."

Momo bit her lip. "That's… a terrifying thought."

Ryoma shrugged. "It's just science."

Momo shook her head. "No, it's more than that. If what you're saying is true, then your Quirk isn't just about moving metal—it's about controlling forces that exist in everything."

She looked at him seriously. "Ryoma, have you thought about what that means?"

Ryoma met her gaze, his expression unreadable. "I have, for a long time."

Momo studied him for a moment longer, then sighed, rubbing her forehead. "I just… I don't know. I trust you, but if someone with your power ever lost control…" She trailed off, not wanting to finish the thought.

Ryoma knew what she was implying. He had considered it too.

As Ryoma watched Momo process everything he had just told her, he couldn't help but be impressed.

Most people wouldn't have understood even a fraction of what he had explained from the first time . Yet Momo had grasped the core concept almost immediately. For someone their age, that was rare.

She wasn't just intelligent; she was perceptive. Even though he had only hinted at the implications of his Quirk's full potential, she had already started thinking ahead, considering both the possibilities and the dangers. That level of foresight was something even adults lacked.

A small smirk played on Ryoma's lips. I really did make the right call befriending her.

It wasn't easy finding people he could actually hold a conversation with. Most of his classmates were either too immature or too focused on trivial things to keep up with his train of thought. But Momo?

She had potential. A lot of it.

And, more than that, she made his days as a teenager… a little less boring.

For once, it was nice to have someone to talk to.

But enough of that—there was an experiment to run.

"Hey rich queen," he said finally and poked at her forehead to gain back her attention.

"Don't worry much, I won't lose control that easily, okay?"

Ryoma reassured her.

Momo let out a breath, forcing a small smile. "Then you'd better train hard, because I think you're only beginning to realize what you're capable of."

Ryoma smirked slightly. "That's the plan. And besides, magnetism isn't just about destruction. Let's test my experiment, I will show you."

______________________

Momo set the Wi-Fi router on the table, next to a copper coil and a few metal components she had created earlier. She adjusted her glasses, watching Ryoma curiously.

"So," she began, "if your Quirk lets you manipulate magnetic fields, how exactly do you plan to interact with Wi-Fi signals?"

Ryoma crossed his arms, his expression thoughtful. "I've been experimenting with my Quirk recently. It's not just magnetism anymore. I can generate a weak electromagnetic field—barely noticeable, but it's there."

Momo's eyes widened slightly. "Wait, you mean like actual EM waves? Not just affecting metals?"

He nodded. "Magnetism, electricity, and electromagnetism are deeply interconnected in science. Possessing the ability of one along with enough understanding and knowledge would inevitably lead me to master the other two.

But right now, my electromagnetic power is still weak, though, nowhere near the level of a real transmitter. But theoretically, I should be able to manipulate electromagnetic interference. In this case, we can try reducing interference and optimizing the signal transmission of this Wifi router."

"Wait, but this Wifi router is new, my parents just bought it last week. How can there already be a decline in its transmission?", Momo wondered.

Ryoma smirked. "It's not about it. Most routers suffer from signal degradation because of environmental interference—walls, other devices, even the Earth's natural electromagnetic field. If I can stabilize the field around the router, we might see an improvement. Create the high-conductivity copper antenna I told you about."

She placed her hands together, her Quirk activating. A faint glow surrounded them before a sleek, high-conductivity copper antenna appeared in her grasp. She attached it to the router, replacing the standard one.

Ryoma rolled his shoulders. "Let's test it out."

He stepped forward and placed his hand near the router. Closing his eyes, he focused, allowing his electromagnetic field to subtly interact with the Wi-Fi signals.

For a moment, nothing happened. Then, Momo's tablet, which was tracking the signal strength, showed a slight but noticeable increase in stability. The fluctuations in the signal became more uniform, reducing the usual dips in connection quality.

The erratic spikes and dips on the graph started leveling into a more stable wave pattern. The packet loss percentage, which indicated how many data packets failed to transmit properly, dropped from 6.3% to 2.1%.

Momo's brows lifted in amazement. "You're reducing interference! The connection is holding steadier now."

Ryoma kept his focus, feeling the subtle pull of energy as he maintained control over the field. "It's still small-scale, but yeah, that's the idea."

Momo quickly ran a speed test on her tablet. The download and upload speeds remained mostly the same, but the latency decreased, meaning there was less delay in data transmission.

"This is incredible," she murmured. "The router isn't any stronger, but you've made it more efficient by suppressing unnecessary fluctuations."

"Well, there's a way to boost the speed if you want. The engineering behind its mechanism is complicated but I can study it given enough time and design the modifications while you can create the components."

Momo raised an eyebrow. "Are you serious?"

"Want to experience NASA's wifi everyday in your house?", Ryoma asked jokingly.

"Alright now that's just straight up illegal, Ryoma!", Momo said.