They say lightning never strikes the same place twice.
They're wrong.
My name is Kaito Hyoudou, and I need you to do one thing for me: believe in the impossible. Because my story starts with the most impossible thing of all—waking up at age five in a world that shouldn't exist, as the younger brother of a character I'd only known as fictional.
Let me take you back to the beginning. My real beginning.
Age 5 - The Realization
I have a crystal-clear memory of the moment I understood what had happened to me.
I was five years old, sitting in a bedroom I shared with a boy named Issei, watching him play with action figures. And suddenly, like a dam breaking, memories flooded back. Not the fragmentary, dreamlike memories of early childhood, but real memories. Adult memories.
Of another life. Another world.
I'd been older—mid-twenties, working a dead-end job, living alone in a small apartment. I remembered anime marathons on weekends, light novels stacked beside my bed, the particular guilty pleasure of watching High School DxD despite its reputation as trashy ecchi.
And now I was in it.
The boy playing across the room—that was Issei Hyoudou. The protagonist. The future Red Dragon Emperor who would gather a harem of beautiful women and fight gods and devils.
Which meant I was… what? A side character? An OC insert? The universe's idea of a joke?
I spent the next week in a state of quiet panic, testing the boundaries of my situation. The language was Japanese, but I understood it perfectly—spoke it natively, even though my previous life had been in English. My "parents" were Issei's parents, warm and loving and completely oblivious to the fact that their younger son was having an existential crisis.
And most importantly: I had no Sacred Gear. I could feel it, that absence. In a world where Issei would eventually awaken the Boosted Gear, where power was measured in demonic abilities and holy swords and dragon supremacy, I was… normal.
Completely, utterly, disappointingly normal.
"Kaito! Come play!" Issei called, waving a plastic superhero at me.
I looked at my brother—and he was my brother now, regardless of my memories—and made a decision. I couldn't change what had happened. I couldn't go back to my old life, assuming it had even been real and not just false memories implanted in a five-year-old's brain.
But I could use what I knew.
"In a minute," I said, my child's voice strange in my ears.
I knew what was coming. The fallen angel Raynare. The death and resurrection. The Rating Games. Riser Phenex. The war between factions. I had years to prepare, to figure out how someone without powers could survive in a world of supernatural beings.
I just had to be smart about it.
Age 7 - The Training
The playground incident happened exactly as I half-remembered it would. Three older kids cornering Issei, mocking him. And despite my adult mind screaming that this was stupid, that I was five years too early to matter in the main plot, I couldn't watch my brother get hurt.
So I fought. And got my ass kicked, obviously.
But it gave me the excuse I needed.
"Dad," I said the next morning, nursing bruises I could have avoided if I'd just stayed out of it. "I want to learn how to fight."
In my previous life, I'd never been athletic. Never trained, never pushed myself physically. I'd been soft, comfortable, mediocre.
Not this time.
If I couldn't have supernatural power, I'd build physical power. Discipline. Skill. I'd become someone who could at least survive in a world of monsters, even if I could never match them.
Issei quit after a few months, just like I knew he would. The canon Issei was many things—brave, determined, loyal—but dedicated to martial training wasn't one of them. He was meant for other paths, other powers.
But I kept going. Four times a week, then five, then six. I pushed myself harder than the senseis expected, than my body wanted, than made sense for a child my age.
Because I knew what was coming. Devils. Fallen angels. Stray exorcists. A world where weakness meant death, and death might not even be an escape.
"You're unusually driven for someone so young," Sensei Takahashi told me after I won my first tournament. "What are you preparing for?"
The end of the world, I thought. Trihexa. The Khaos Brigade. Gods and dragons and things that could erase cities.
"I just want to be strong," I said aloud.
It was the truth, if not the whole truth.
Age 12 - The Science
The injury was real, but my response to it was calculated.
I'd been waiting for an excuse to dive deep into science, to build a knowledge base that could help me understand the supernatural physics of this world. Sacred Gears operated on principles that weren't quite magic and weren't quite physics. Devils used magic systems with consistent rules. The Boosted Gear doubled power every ten seconds—that implied energy conservation violations or external power sources.
I needed to understand it all.
So I studied. Physics, chemistry, biology, engineering. I devoured MIT OpenCourseWare, corresponded with university professors, built projects that tested the boundaries between science and the supernatural I knew existed.
"Kaito's in his room again," Issei would say, and I'd hear the distance growing between us.
It hurt. In my previous life, I'd been alone by circumstance and apathy. In this life, I was alone by choice and necessity. I couldn't explain to my brother why I was so driven, why I studied like the world depended on it.
Because in a very real sense, it might.
I watched Issei grow into his canonical personality—the pervert, the dreamer, the boy who wanted a harem and wasn't ashamed to admit it. Part of me wanted to warn him about Raynare, about the betrayal coming on his first date. Part of me wanted to accelerate his development, push him toward his destiny faster.
But I couldn't. Interfering with canon was dangerous. Butterfly effects could spiral out of control. What if I accidentally prevented him from meeting Rias? What if my interference meant he never got the Boosted Gear?
So I stayed back. Studied. Trained. Prepared for a future I knew was coming but couldn't quite prevent.
And tried not to think about how lonely it was, knowing everything and being able to change nothing.
Age 15 - Five Months Before the Lightning
The entrance exams for Kuoh Academy were both inevitable and necessary.
In my previous life, I'd known the broad strokes of the plot. Kuoh Academy was where everything happened. Where Issei would meet Rias, where the supernatural world would collide with the mundane, where the story truly began.
I needed to be there. Not as a participant—I had no illusions about my role—but as an observer. Someone who could maybe help from the shadows, who understood the threats before they emerged.
Plus, the science facilities were legitimately excellent. That wasn't just rationalization.
I studied obsessively, aced the exams, and got my acceptance letter. Issei had already been there for a year, building his reputation as part of the "Perverted Trio." I'd cringed watching it happen, knowing it was necessary character development but still embarrassed by association.
"Just try not to make me look bad, little brother," Issei joked when he heard I'd gotten in.
You're going to make yourself look bad enough, I thought. Then you'll die, come back as a devil, and eventually save the world. It's your path, not mine.
"I'll do my best," I said instead.
I had five months before the school year started. Five months to prepare, to plan, to figure out my role in a story I wasn't supposed to be part of.
Then the lightning struck, and everything changed.
The Lightning Strike - The Real Story
I was in the science lab late on a Thursday evening, alone by design. The storm outside was fierce, but I'd checked—this wasn't part of canon. No significant event was supposed to happen to me on this date.
I was experimenting with electromagnetic fields, trying to understand if there was any overlap with the magical energies I knew existed in this world. It was slow work, frustrating work, but it was something.
Then time slowed.
And I realized, with perfect clarity: I'd been an idiot.
I wasn't a background character. I wasn't safe just because I wasn't in the original plot. This was a real world now, with real physics and real dangers and real consequences for the guy stupid enough to mess with electromagnetic equipment during a thunderstorm.
The lightning came through the window like divine judgment.
The pain was indescribable. But underneath it, threading through the agony, I felt something else. Something vast and infinite and utterly impossible by the rules of either world I'd known.
My last coherent thought before darkness claimed me was: This isn't DxD canon. This is something else entirely.
The Coma - Understanding
Nine months in darkness.
Nine months of my family suffering, thinking they'd lost me.
Nine months of my consciousness floating in an endless sea of golden light and crackling energy, being unmade and remade at the fundamental level.
I dreamed of speed. Of moving so fast that time became negotiable, that space was just a suggestion. I dreamed of a realm that existed outside normal reality, outside the supernatural rules of the DxD universe I'd been dropped into.
The Speed Force.
I knew this. Even without being conscious, my memories supplied the context. DC Comics. The Flash. Barry Allen, Wally West, countless speedsters connected to an extra-dimensional energy that powered them.
But this wasn't DC Comics. This was High School DxD. Or it was supposed to be.
Unless…
Unless my presence had already changed things more than I'd realized. Unless the universe was adapting, incorporating new elements, creating something hybrid.
Or unless I'd never understood what world I was really in.
When I finally woke up, weak and disoriented in a hospital bed, the first thing I checked was my knowledge. Did I still remember the DxD plot? Yes. Did I still remember my previous life? Yes. Did I still remember DC Comics and the concept of speedsters? Yes.
All of it was still there. All of it was real.
Which meant I was in a world that was bigger and stranger than I'd ever imagined.
And I had the Speed Force.
Discovery - The New Reality
The physical therapy should have taken months. I was back to full strength in three weeks, and that was me deliberately holding back.
Because I could feel it now. The energy humming beneath my skin, waiting to be used. Every cell in my body vibrated with potential speed, with the promise of velocity that broke physics.
I tested it carefully at first. A burst of speed in the hospital hallway when no one was looking—there and back before the nurse turned around. A quick run through the backyard at night, fast enough that I was invisible to any casual observer.
Then I went to the warehouse district and really let loose.
God. God. Nothing in either life had prepared me for this feeling. I ran faster than cars, faster than my eyes could track, faster than thought. The world became a blur of color and light, and golden lightning crackled in my wake.
This was power. Real, tangible, supernatural power in a world where I'd thought I'd be forever mundane.
But I understood immediately what it meant: I was no longer a background character. I was no longer safe in my knowledge of canon. I'd become something new, something that didn't exist in the original story.
An X-factor. A variable. A speedster in a world of devils and angels.
I needed to understand what I'd become. So I studied—every piece of information about the Flash, about speedsters, about the Speed Force I could remember. I cross-referenced it with what I knew about the DxD universe, looking for overlap, for rules, for limitations.
The Speed Force operated outside normal physics. But the DxD universe had its own supernatural physics—sacred gear mechanics, magic systems, dimensional theory. How did they interact? Where did one end and the other begin?
I spent weeks testing, experimenting, pushing my limits. I learned to vibrate through solid matter. To generate lightning. To perceive time differently, to exist in the spaces between moments.
And I realized something crucial: the Speed Force in this world was mine. It wasn't like Sacred Gears, which came from God's system and had defined parameters. It wasn't like magic, which required rituals and circles and contracts with devils.
It was an external force that I'd connected to, something outside the supernatural hierarchy of this world. Which meant I existed in a weird gray area—powerful, but not in any way the factions understood.
That could be an advantage. Or it could paint a target on my back.
I needed protection. I needed a suit.
The Suit - Preparation
Building the suit took three weeks and most of my savings, but more importantly, it took knowledge.
I knew what worked from my memories of the Flash TV show. Aerodynamic design, friction-resistant materials, lightning-proof construction. But I also understood the DxD universe's rules—durability was key when you might face devils who could throw city-destroying attacks.
The final product was a synthesis: red polymer fibers reinforced with materials that could withstand both physical and magical damage. Gold accents for electrical conductivity. The white lightning bolt emblem on the chest serving as both symbol and functional element.
When I put it on for the first time and looked in the mirror, I saw someone who existed between worlds. Not quite a devil, not quite human, not quite following any established rules.
I looked like a hero from the comics I'd loved in my previous life.
But I was standing in a world where heroes were measured by different metrics—devil rankings, Longinus-class Sacred Gears, beings who could fight gods.
Where did a speedster fit in that hierarchy?
I didn't know. But I was going to find out.
My name is Kaito Hyoudou. I'm a reincarnated soul from another world, living as the younger brother of a future demon king. I should have been a nobody, a background character with no powers.
Instead, I'm connected to the Speed Force.
And I am this world's Flash.