It was five in the morning.
The sun had only just begun to rise, its golden light barely piercing the thick fog blanketing the city. The streets lay quiet, with only a handful of early risers going about their morning routines. A milkman on his route. A jogger stretching by a lamppost. A street sweeper humming to himself.
And then there was a blur—a teenager sprinting through the mist-covered roads at top speed.
To any ordinary observer, he would've looked like a professional athlete in the middle of an intense training session. His pace, his form, and the sheer speed at which he moved made it seem like he was preparing for the Olympics.
But this was no ordinary boy. This was Issei Hyoudou.
His speed, while laughable to supernatural beings, was nothing short of extraordinary to regular humans. In their eyes, he was superhuman.
As he dashed down the street, breathing steady and limbs pumping with practiced rhythm, only one thought echoed in his mind sun rays are really not kind to devils.
The memory of earlier resurfaced—waking up, removing the suppression band from his arm, and feeling the crushing weight of mental exhaustion hit him like a wave. Despite that, here he was, running with the grace and stamina of a top-tier athlete.
It was surreal.
For a moment, he allowed himself to feel proud of it.
But that moment didn't last.
"Don't get ahead of yourself," came a deep, gruff voice from within his mind. "Your running speed is barely acceptable—even by supernatural standards."
Issei flinched slightly, though not from the pace. Ddraig's voice was impossible to ignore. The Red Dragon Emperor had a presence that filled his very soul whenever he spoke.
He knew the dragon wasn't trying to belittle him. In fact, Ddraig understood. This was the first time Issei had ever felt such physical prowess, and the boy was clearly awestruck by it.
But Ddraig had seen countless hosts over the centuries—and he had learned one thing: newfound power could just as easily destroy someone if they weren't properly grounded. Overconfidence was a death sentence.
Issei's mood dipped slightly at the dragon's words, but he didn't argue. Ddraig was right.
He couldn't afford to get drunk on this speed—especially when he knew full well that the enemies ahead would make his current pace look like a toddler's crawl. Some could break the sound barrier casually. Others moved faster than the eye could see.
Compared to that, his current speed was laughable.
But even so, he allowed himself a small smirk and muttered aloud, "Hey, cut me some slack. Let me enjoy it for now. I've never gone this fast in my life."
Ddraig remained silent at that, though if Issei had been paying attention, he might've felt the faintest twinge of amusement echo through their bond.
There was one question that had been nagging at Issei since he woke up.
He had been holding it back until now, but the irritation—both mental and physical—was starting to become too much to ignore.
"Hey, Ddraig," he asked between breaths, his legs pumping steadily as he continued his morning run. "Why did you make me take off the band and stop taking the pills? You know they were helping me control my power—and shielding me from the sunlight."
To Issei, those items were practically cheat codes. The band suppressed his unstable energy, and the pills neutralized the burning headaches caused by his devil weakness to sunlight. Without them, his mornings were migraines wrapped in muscle strain.
Ddraig's voice echoed from deep within him—calm, ancient, wise.
"You need to understand something, boy. That band and those pills are crutches," he said, his tone like a stern mentor. "They were made for those who are too weak to stand on their own yet. They help you walk when you've just learned to crawl—but you are not meant to rely on them forever."
Issei frowned but kept running, letting the dragon's words sink in.
"Think of it like this: they're good for the short term. But in the long run, they'll hold you back," Ddraig continued. "If you become too dependent on them, you'll never learn to control your power fully. You'll never be able to fight in the morning sun—or against someone who uses light-based magic. And that band... it will become a leash, not a support. You'll cap your own growth."
The words hit hard—but they weren't wrong.
As Issei ran through the foggy town streets, he thought about the rest of the Peerage. He couldn't remember seeing any of the others wearing such a band. They moved with ease, fought without hesitation, and stood beneath the sun without wincing.
They'd adapted. They'd gained control.
And if they could do it... then so could he.
He had nearly completed a full lap around the entire city by now, his body dripping with sweat, his muscles warming into a rhythm. Still, his breathing was calm—far better than it had ever been before.
That's when another thought struck him.
"Wait a second," he said aloud, eyes narrowing. "You never told me how long I'm supposed to be doing this. How many laps?"
Ddraig's voice returned—this time with a sadistic edge that made Issei's stomach drop.
"One hundred laps around the town."
Issei nearly tripped.
"And once you're done, you'll do one thousand push-ups. Then one thousand squats. After that, you'll head to school and request martial arts and magic training from Rias."
Issei groaned, his legs still moving on autopilot as sweat dripped from his brow. His breath came in steady huffs, but irritation was beginning to creep into his tone.
"Hey," he muttered aloud, addressing the voice inside him, "with this insane training regimen of yours, I don't even have any free time to myself. I'm going to be exhausted every single day! What if there's some kind of emergency? I'll be too drained to do anything—I'll die, you know?"
His complaint wasn't baseless. It was a fair point, and one that any reasonable person would raise. But Issei had forgotten one important detail:
Ddraig wasn't just any voice in his head.
He was a dragon—the Red Dragon Emperor—and over the centuries, he had been partnered with countless users of the Boosted Gear. He had trained them, watched them grow… and watched many of them fall because of their own arrogance.
Every time a new host awakened his power, they became intoxicated by it—thinking they stood at the top of the world just because they bore the name of the Red Dragon Emperor. And because of that pride, most of them did the bare minimum when it came to training.
Ddraig had learned, over centuries of mistakes, how to break that arrogance early.
Which is why, instead of sympathy, Issei received a lecture.
"You need to understand something," Ddraig said, his deep voice echoing through Issei's mind like the voice of a stern mentor. "You are no longer human. You are a devil—one who bears the power of a dragon. And not just any dragon—me."
There was a moment of silence, the weight of Ddraig's words pressing down on Issei's shoulders.
"That makes you a hybrid of two of the most resilient and combative races in existence. Devils, born from the original Lucifer to fight Heaven, possess incredible stamina and natural regeneration. Dragons, by their very nature, are a race of warriors—built for battle, bred to survive. Our recovery is on a level few other races can match."
Ddraig's voice hardened with conviction.
"So this 'hellish training,' as you call it, might seem overwhelming now. But you'll adapt. Your body is already changing. In two to three weeks, your stamina and recovery will double—perhaps even triple. What feels impossible now will become routine."
Issei gritted his teeth—not in anger, but in reluctant understanding.
Without wasting any more energy arguing with Ddraig, he decided it was better to just focus and finish the task at hand. Complaining wouldn't lessen the pain, and he still had school to attend afterward.
He continued running, pushing himself past every limit his body screamed at him to respect. Around the city he went—again and again—until he had completed his sixtieth lap.
That was when his body finally gave out.
His legs buckled beneath him, and he collapsed to the ground. He lay there, gasping for air, lungs burning like they had been set ablaze. Sweat poured from his skin in rivers, soaking his clothes and matting his hair to his forehead.
Every breath he drew felt like fire in his chest.
Every bone in his legs screamed in agony, as if they were cracked or turned to jelly. His muscles spasmed from overuse, raw and trembling as though they were about to tear apart.
He shakily propped himself up on his elbows, but didn't dare try to stand—he already knew what would happen if he did. His vision was still blurry, and his arms were trembling with fatigue.
Through ragged breaths, he muttered, "Can I go home now...? I still have school, you know."
For once, Ddraig didn't offer a lecture.
The great dragon's voice, when it finally came, was calm and understanding. "Fine. Let's go home."
As Issei slowly stumbled toward his house, Ddraig remained silent—though not idle. Even now, the ancient dragon was carefully recalibrating the training regimen, adjusting it based on Issei's current physical limits. There was no point in assigning tasks the boy couldn't yet complete. Proper growth came from challenge—not suicide missions.
Issei's Home
As Issei stepped through the front door of his house, he never expected to be greeted by the deeply worried faces of his parents. His mother, Miki, looked downright frantic, and his father, Gorou, stood behind her with a grim, displeased expression.
Before he could even take off his shoes, both of them rushed toward him.
Miki grabbed him by the shoulders, eyes scanning him head to toe. Her fingers trembled as she checked him over, looking for any sign of injury. The only thing she found was that his entire body was drenched in sweat, as if he had run a marathon.
Once she confirmed there was nothing physically wrong with him, her worry transformed into something else entirely—anger.
"Where were you!?" she snapped, her voice rising with emotion. "I went to your room this morning and you were gone! Do you have any idea how worried I was?!"
Gorou didn't say anything right away, but the look on his face made it clear he shared his wife's concern—and her displeasure. He simply stood back and let Miki unleash her frustration on their son.
Issei blinked, stepping back instinctively, startled by their reactions. He wasn't used to this. In all his life, he'd never seen his parents this upset—certainly not at him.
Caught completely off guard, he fumbled for a response, his voice soft and guilty. "I… I was just out jogging…"
That answer only confused his parents more.
Miki and Gorou stared at him, brows furrowing as if trying to decide whether he was joking or lying.
"Jogging?" Gorou repeated slowly, clearly unconvinced. "Since when did you find that interesting?"
Miki folded her arms. "You've always hated physical activity. We've tried to get you into sports for years, remember? Your coaches always said you had good potential, but you quit every time after just a few days."
Their disbelief was obvious—and justified. This wasn't just a sudden change. It was drastic.
To them, it felt like their son had become someone entirely different overnight.
Issei clenched his jaw in frustration, silently cursing the original Issei—the version of himself that had apparently gone through life avoiding even the most basic forms of physical activity.
"Seriously? You hated sports so much you couldn't even keep up jogging for a week? Thanks for nothing…" he muttered in his mind.
Desperate to smooth things over, he conjured up the most believable lie he could think of—one rooted in the part of Issei's personality his parents knew all too well.
"I, uh… I made some new friends at school," he began, forcing an awkward laugh and rubbing the back of his head, "and they told me that the way I am right now, I'll never get a girlfriend."
He winced inwardly at how cringe it sounded, but kept going.
"They gave me advice—told me I should start jogging, get in shape… and well, that's why I went out early this morning."
It wasn't a good excuse, not really. But it was believable. After all, if there was one thing his parents knew about him, it was his notorious obsession with the opposite sex.
Sure enough, their expressions softened just a little—clearly skeptical, but not outright dismissive. It was enough.
But the questions didn't end there.
Miki narrowed her eyes. "Then why didn't you answer your phone? I called you at least ten times!"
Issei blinked, confused. "Phone?"
His hand shot down to his pocket, and he began patting himself frantically. His pockets were empty.
He checked his jacket. His waistband. Nothing.
No phone.
His mind raced. I'm sure I took it when I left… So where—? Then it hit him.
He must have dropped it somewhere while running.
From the way his parents watched him desperately search his body, it didn't take long for them to realize the truth. Their sighs—one frustrated, the other tired—told him everything.
They understood.
He'd lost it.
Both Miki and Gorou let out a deep sigh, allowing their anger to fade. After all, their son hadn't done anything wrong. If anything, Issei was trying to improve himself—and being angry at him for that would do more harm than good.
Gorou was the first to speak, his voice calm but firm. "I know you're old enough to want some independence. You don't need to tell us everything going on in your life… but at least let us know when you're leaving the house."
It wasn't an unreasonable request—and Issei knew it. He couldn't argue against that kind of concern, not after scaring them like he had. So he simply nodded and said, "Yeah… sorry. I will."
Satisfied with his answer, both parents seemed to relax. Miki offered a small smile and added, "Go wash up now. You still have school to attend, remember?"
As soon as she reminded him, Issei's eyes widened. Right—school!
Mustering what little strength he had left in his aching legs, he forced himself to head upstairs to get ready, dragging his body one step at a time as if gravity had tripled.
Once he was gone, his parents exchanged a knowing look—a quiet agreement passing between them that this morning's drama didn't need to be brought up again.
Miki was the first to break the silence. "We should buy him a new phone now that he's lost his."
Gorou gave a small grunt of acknowledgment. "I'll pick one up after work."