The transition from nine to ten years old marked a turning point in Arthur's development. Not because of any single breakthrough, but because everything began accelerating.
His quirk evolution six months prior had unlocked something fundamental. Where before his progress had been steady and incremental, now it was exponential. His body adapted faster to training. His quirk responded more readily to his will. The energy reserves that had once seemed vast but distant were becoming accessible.
Arthur stood in Tanaka's gym on a winter morning, his breath misting in the cold air. The building's heating had broken again—Tanaka refused to fix it, claiming the cold was "good training for temperature resistance." Arthur suspected the old man was just cheap, but he'd learned not to complain.
"Show me your blade," Tanaka commanded from across the room.
Arthur raised his right hand and manifested his energy sword. Golden light crystallized into a solid blade, three feet long, stable and gleaming. He'd chosen this length deliberately—long enough to have reach, short enough to control precisely. The manifestation took less than a second now, and he could maintain it indefinitely as long as he didn't exert himself otherwise.
"Good. Now the left hand."
This was newer. Arthur raised his left hand and concentrated. A second blade materialized, identical to the first. Dual-wielding had been Tanaka's idea—why limit himself to one sword when he had two hands?
The old man nodded approval. "Maintain both. I want to see thirty minutes continuous."
Arthur settled into a ready stance and focused. Maintaining two blades was significantly harder than one—not double the difficulty, but perhaps triple. The energy flow had to be balanced perfectly between both manifestations, requiring a level of control that had taken months to develop.
But Arthur had months of practice now. The blades hummed with steady power, unchanging, as minutes ticked by.
Tanaka circled him slowly, observing with those sharp eyes that caught every micro-tremor, every flicker of instability. "Your control is excellent. But control alone won't save you in a real fight. You need to be able to maintain these while moving, while defending, while
attacking. Real combat isn't a meditation exercise."
As if to emphasize his point, Tanaka suddenly hurled a training weight at Arthur's head.
Arthur's body moved before his mind processed the threat. He swayed left, the weight whistling past his ear, both blades remaining perfectly stable throughout the motion. Another weight came from a different angle. Arthur ducked, twisted, his enhanced reflexes tracking multiple projectiles as Tanaka launched them in rapid succession.
Through it all, the energy blades never flickered.
"Better," Tanaka grunted when the barrage ended. "Much better. Six months ago, you'd have lost one blade within three seconds. Now you can maintain focus under pressure. That's the difference between a technique and a skill."
Arthur allowed himself a small smile. The praise was rare enough to be meaningful.
"Don't get cocky," Tanaka added, as if reading his thoughts. "You're good for a ten-year-old. Hell, you're exceptional for a ten-year-old. But you're still a ten-year-old. I could take you down in five seconds if I wanted to."
"Four seconds," Arthur corrected. "You're getting old, sensei."
Tanaka barked a laugh. "Cheeky brat. Drop and give me three hundred push-ups. With the blades active."
Arthur groaned but complied. This was a favorite torture of Tanaka's—making him exercise while maintaining his energy manifestations. It trained both his physical stamina and his mental focus simultaneously, forcing his body and quirk to work in harmony even under strain.
As Arthur pushed through the exercise, arms burning, blades still glowing steadily, his mind wandered to the larger picture. He was ten now. Six years remained until he turned sixteen. Six years to bridge the gap between "exceptional ten-year-old" and "strongest hero alive."
The math was still brutal. But it was becoming less impossible with each passing month.
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Arthur's training had expanded beyond just Tanaka's gym. He'd discovered that Yokohama had several hero-watching spots—places where civilians gathered to observe pro heroes in action during villain attacks or rescue operations. Most of the spectators were fans or aspiring hero students. Arthur went to study.
Every hero had their own style, their own approach to using their quirk. By observing them in actual combat situations, Arthur could analyze what worked and what didn't, what strategies proved effective and which left openings.
Today, a villain with a concrete-manipulation quirk had taken hostages in a downtown building. Three pro heroes had responded: Kamui Woods, whose branching limbs could restrain and rescue; Mt. Lady, whose gigantification made her ideal for blocking escape routes; and a hero Arthur didn't recognize with some kind of speed-based quirk.
Arthur watched from a safe distance, his analytical mind dissecting every action. Kamui Woods used his branches to simultaneously rescue hostages and restrain the villain—excellent multitasking, leveraging his quirk's versatility. Mt. Lady positioned herself to prevent collateral damage from concrete projectiles, serving as a mobile shield for civilians. The speed hero darted in and out, distracting the villain while the others worked.
Teamwork. Coordination. Using each quirk's strengths to cover others' weaknesses. This was how professional heroes operated.
But Arthur also noted the flaws. The speed hero moved predictably, following the same attack patterns. The villain could have capitalized on that if he'd been more observant. Mt. Lady's gigantic size, while useful as a shield, made her a target and limited her mobility. And Kamui Woods, for all his versatility, seemed to struggle with divided attention—his branches were powerful but each required conscious control.
These observations went into Arthur's mental database. Not to criticize—these were professional heroes doing their jobs well—but to learn. To understand the realities of hero work beyond what books and training could teach.
The fight concluded with the villain restrained and all hostages safe. The crowd cheered. Arthur slipped away, already thinking about how he would have approached the same situation differently.
With his energy blades, he could have cut through the concrete defenses easily. His enhanced speed would let him rescue hostages faster. His quirk's durability was approaching the point where concrete projectiles wouldn't significantly harm him.
But he was ten. His body, despite years of enhancement, was still small. Still developing. He had the techniques and the growing power, but not yet the physical frame to fully utilize them.
Patience, Arthur reminded himself. The foundation was nearly complete. Soon, he could start building the upper floors.
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That evening, Arthur returned home to find his mother waiting with an unusual expression—part concern, part pride, part something he couldn't quite identify.
"Arthur-kun, sit down please. We need to talk."
Arthur's heart rate spiked. Had she discovered his late-night training? His trips to watch hero fights? The increasingly obvious gap between his capabilities and what a normal ten-year-old should possess?
He sat at the kitchen table, keeping his expression neutral. "What's wrong, Mama?"
Akari pulled out a photograph and set it on the table. It showed Arthur at Tanaka's gym, manifesting his dual energy blades. Someone had taken it through the window.
"A concerned citizen," Akari said quietly, "sent this to your school, worried that a child was using his quirk unsupervised in a dangerous manner. The school contacted me. They wanted to know if I was aware that my son was training with what they called 'potentially lethal quirk manifestations.'"
Arthur said nothing. There was nothing to say. The evidence was irrefutable.
"I told them," Akari continued, "that of course I knew. That you were training under professional supervision. That everything was legal and safe." She paused. "I lied to protect you, Arthur. Now I want the truth. All of it."
The moment stretched. Arthur could lie again, could minimize, could deflect. But looking at his mother's face—at the woman who had loved him unconditionally for ten years, who had protected him, who had pretended not to notice how different he was—he couldn't.
"I've been training to become a hero," Arthur said simply. "Seriously training. For years now. Tanaka-sensei is a retired pro hero who's been teaching me combat techniques. The energy blades are my quirk's evolved application—they're stable, controllable, and yes, potentially dangerous. Which is why I only practice them in controlled environments."
"You're ten years old."
"I know."
"Most children don't start serious hero training until middle school at the earliest."
"I know."
"You could hurt yourself. You could damage your development. You could—" Akari's voice cracked slightly. "Arthur, why are you pushing so hard? Why can't you just be a child for a little while longer?"
And there it was. The question Arthur had known was coming eventually. The question he'd been dreading because he couldn't answer it honestly.
I'm not really a child, he wanted to say. I'm a warrior-king reborn, trying to correct the mistakes of my past life by becoming strong enough to protect everyone this time.
But he couldn't say that. So he said the only truth he could share.
"Because I failed once, Mama. I failed people who were depending on me, and they died because I wasn't strong enough. I can't fail again. I won't."
It wasn't the whole truth. But it was enough truth that his mother heard the conviction behind it, the weight of guilt and determination that no ten-year-old should carry but which Arthur bore nonetheless.
Akari was quiet for a long moment. Then she reached across the table and took his hand.
"I don't know what happened to make you feel this way. I don't know if it was something real or something you dreamed or something in between. But Arthur, listen to me—you're not responsible for saving everyone. You're not responsible for being perfect. You're allowed to be human. You're allowed to fail and learn and grow. That's what childhood is for."
"What if I don't have time for that?" Arthur asked quietly.
"Time for what?"
"To grow slowly. To fail and learn. What if people need me to be ready sooner?"
Akari squeezed his hand. "Then we'll deal with it together. But I need you to promise me something."
"What?"
"That you'll be careful. That you won't push yourself so hard you break. That you'll remember you have people who love you and want you safe. Can you promise me that?"
Arthur looked at his mother and saw the fear in her eyes. Not fear of him, but fear for him. She knew he was special, knew he was driven by something beyond normal childhood ambition. And she was terrified of what that might cost him.
"I promise," Arthur said. And meant it. Not that he'd stop training—he couldn't, wouldn't do that. But that he'd be more careful. More mindful of his limits. Because his mother was right—he had people who loved him now. People he'd fight to come home to.
Akari nodded, satisfied. "Okay. Now, tell me about this Tanaka-sensei. If you're going to train with someone, I want to meet him and make sure he's actually qualified and not some vigilante teaching children dangerous techniques in a sketchy gym."
Despite everything, Arthur smiled. "He's qualified, Mama. But yes, I'll introduce you."
The conversation continued, with Arthur explaining his training in terms his mother could accept. He didn't mention the late-night construction site visits or the deliberate quirk overload experiments or the calculated risks he took. But he was honest about his goals, his
dedication, and his progress.
By the end, Akari had extracted a promise that Arthur would train no more than five days a week, would maintain his grades, would continue having a normal social life, and would let her or Tanaka know if he was injured or struggling.
It was more oversight than Arthur wanted. But it was also, he had to admit, probably necessary. He'd been so focused on his goal that he'd lost perspective on the fact that he was still a child, still needed guidance, still could benefit from having adults who cared about his wellbeing.
His mother wasn't an obstacle to his training. She was an anchor keeping him grounded. Keeping him human.
And that, Arthur was learning, might be just as important as becoming strong.
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True to her word, Akari visited Tanaka's gym the next day. Arthur waited nervously, unsure how the meeting would go. His mother could be surprisingly fierce when it came to protecting him.
Tanaka, for his part, cleaned the gym and dressed in his old hero costume—slightly moth-eaten but still recognizable. When Akari arrived, he bowed formally.
"Himura-san. Thank you for allowing me to train your son. He's told me about you."
Akari's eyes narrowed. "And you thought it appropriate to teach combat techniques to a child without parental consent?"
"No," Tanaka said bluntly. "It was inappropriate. I should have contacted you immediately. But Arthur was so serious, so dedicated, and so obviously in need of proper instruction that I made a judgment call. If you want me to stop training him, I'll respect that decision."
The honesty seemed to surprise Akari. She studied the old man carefully, taking in the worn but well-maintained equipment, the safety measures visible throughout the gym, the genuine respect in Tanaka's demeanor.
"Show me what you've been teaching him," she said finally.
For the next hour, Tanaka walked Akari through Arthur's training regimen. The sword forms, the physical conditioning, the quirk control exercises. He explained his philosophy—that proper training reduced injury risk, that technique was more important than power, that he pushed Arthur hard but never beyond what the boy could safely handle.
"He's special," Tanaka said quietly. "In my thirty years as a hero and twenty years training students, I've never seen anyone with his combination of talent, dedication, and maturity.
He's going to be a great hero someday. My job is just to make sure he lives long enough to get there."
Akari watched Arthur practice his sword forms, moving with a grace and precision that seemed impossible for a ten-year-old. She saw the energy blades manifest and hold steady, saw the control her son had developed, saw the joy in his face when Tanaka praised a well-executed technique.
"Alright," she said finally. "He can continue training with you. But I want weekly updates on his progress and any injuries. And if I think he's being pushed too hard, this stops immediately. Understood?"
Tanaka bowed again. "Understood. Thank you, Himura-san."
As they left the gym, Akari pulled Arthur aside. "He's a good teacher. And he cares about your safety. But Arthur, remember—you don't have to prove anything to anyone. You're enough exactly as you are."
Arthur nodded, though privately he disagreed. He had everything to prove. To himself, to his past failures, to the future he was trying to build. But he appreciated his mother's concern, appreciated having someone who saw him as just her son rather than a developing weapon.
It was grounding. Humanizing. Exactly what he needed even if he didn't always want to admit it.
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With his mother's approval secured, Arthur's training entered a new phase. Tanaka, freed from worry about angry parents showing up, began pushing harder. Not recklessly—the old man was still cautious—but more intensely.
"You've mastered the basics," Tanaka explained during a session shortly after Arthur's tenth birthday. "Your forms are solid, your control is excellent, your conditioning is exceptional. Now we work on application. Real combat scenarios. Tactics. Strategy."
The training evolved. Where before they'd done basic sparring, now Tanaka created complex scenarios. Multiple opponents. Environmental hazards. Hostage situations. He'd recruit other gym members to play villains, set up obstacles, force Arthur to think tactically while fighting.
"Heroes don't fight in controlled environments," Tanaka reminded him. "You need to be ready for anything. Adaptability is just as important as skill."
Arthur threw himself into the new challenges. Each scenario taught him something new—about timing, positioning, reading opponents, managing multiple threats. His warrior instincts from his previous life began merging with the tactical thinking of this modern era,
creating something unique.
His energy blades proved incredibly versatile. He could manifest them at different lengths—from dagger-sized for close quarters to extended reach for distance. Could adjust their brightness to blind opponents or dim them for stealth. Could even partially solidify them to create barriers rather than cutting edges.
But the most important development came three months after his tenth birthday, during an intense training session.
Arthur was sparring against three adults simultaneously—gym members Tanaka had recruited, all with combat experience. The scenario was a hostage rescue: Arthur had to disable the "villains" and reach the "hostage" (a training dummy) within three minutes.
Two minutes in, Arthur was struggling. The adults coordinated well, cutting off his angles, forcing him into defensive positions. His energy blades were useless if he couldn't close distance to use them.
Then instinct took over. The same instinct that had once guided Excalibur's beam attack. Arthur didn't think—just acted.
He slashed with his right-hand blade, but instead of a simple cut, he released a wave of golden energy. It wasn't solid like his blade. More like compressed air, a visible shockwave of his quirk's power that exploded outward in a crescent arc.
The three adults dove for cover as the wave passed over them, slamming into the far wall hard enough to crack the concrete.
Arthur stared at his hand in shock. He'd done it. He'd released his energy as a projectile attack. Not a blade, but a wave. A ranged technique that didn't require closing distance.
Tanaka was already running over, checking that no one was injured. Fortunately, Arthur's instinctive control had kept the attack non-lethal—more concussive force than cutting edge. But the power was undeniable.
"That," Tanaka said once he'd confirmed everyone was okay, "was both incredibly dangerous and incredibly impressive. Can you do it again?"
Arthur tried. Focused on that feeling, that instinct. Slashed and released—
Another golden wave erupted from his blade, smaller than the first but more controlled.
"Unbelievable," Tanaka muttered. "Your quirk just evolved again. That's not just manifestation—that's energy projection. Do you know what this means?"
Arthur knew exactly what it meant. He'd taken another step toward recreating Excalibur's ultimate technique. The beam of light that could destroy armies. He wasn't there yet—these
waves were crude, unrefined, a tiny fraction of what he'd eventually achieve. But the foundation was there.
The path was clear.
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The rest of Arthur's tenth year was consumed by mastering his new technique. The energy waves were powerful but difficult to control. Too much power and they became lethal. Too little and they were useless. The balance required precise calibration.
Tanaka helped him develop a training regimen focused on control and efficiency. They started with stationary targets, then moving ones, then reactive opponents. Arthur learned to adjust the wave's size, shape, and power on the fly, adapting to different combat situations.
By the time Arthur turned eleven, he could consistently generate energy waves at three power levels: a stunning burst for non-lethal takedowns, a moderate slash for cutting through obstacles, and a maximum output that could punch through concrete walls.
More importantly, his overall power continued climbing. His base physical abilities now matched a trained adult athlete. With his quirk active, he could lift several hundred pounds, run faster than most vehicles in the city, and react to threats with superhuman speed.
But Arthur remained aware of how far he still had to go. He'd watched pro heroes in action enough to know that the top tier—All Might, Endeavor, the strongest heroes—operated on a completely different scale. All Might could change weather patterns with his punches. Endeavor's flames could melt through anything. These weren't just strong—they were forces of nature.
Arthur needed to reach that level. And then surpass it.
Five years remained. Five years to transform from "exceptionally talented child" to "strongest being alive." The challenge was enormous. But Arthur had faced impossible odds before.
And this time, he wouldn't fail.
On the evening of his eleventh birthday, Arthur stood alone in Tanaka's gym. His teacher had gone home, leaving Arthur to practice in private. This had become ritual—after each birthday, Arthur would assess his progress, honestly evaluate where he stood.
He manifested both energy blades. Three feet long, perfectly stable, gleaming with golden light. Beautiful and deadly.
Then he dismissed them and focused. Drew on his quirk's full power, felt it surge through his body, enhance every muscle, sharpen every sense. This was Royal Core at maximum output
—the culmination of seven years of training and enhancement.
Arthur jumped. Not a normal jump, but a quirk-enhanced leap that launched him twenty feet straight up, nearly to the gym's ceiling. He landed silently, the impact absorbed by his enhanced legs.
Speed next. Arthur sprinted the length of the gym in under two seconds, faster than most professional athletes, then stopped instantly without skidding.
Strength. He walked to the heavy bag—three hundred pounds of dense material—and punched it. The bag exploded off its chain, flying across the gym to crash into the far wall.
Arthur looked at his fist. Not even bruised. His body could handle forces that would shatter normal bones.
Finally, he raised his hand and manifested his blade one more time. Then he slashed, releasing a controlled energy wave that carved a clean line across the gym floor.
Seven years of training. Seven years of pushing his limits, evolving his quirk, building his foundation. And the result was clear.
Arthur was no longer a child pretending to be strong. He was legitimately powerful. Not top-tier yet, not anywhere close to his ultimate goal. But powerful enough that most adults would struggle against him in a fight. Powerful enough that weak villains would be no threat.
Powerful enough to start taking the next step.
Five more years. Five more years of this exponential growth. Five more years of evolution and training and pushing past every limit.
And then Arthur would stand among the greatest. Not as their equal.
As their superior.
The thought should have excited him. Instead, Arthur felt a strange calm. This wasn't about pride or glory. It was about being ready. About having the power to protect everyone when the moment came. About never again watching people die because he wasn't strong enough.
Whatever challenges the future held—whatever villains emerged, whatever crises arose—Arthur would be ready.
He was becoming the sword that would cut through any darkness.
One day at a time.
To be continued...
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