Reincarnated in DxD With the 100X System

If my 100X System worked on learning and training, then in theory, I should be able to master spells insanely fast.

But this was DxD's magic system—not something I could just brute-force with raw talent alone.

I needed actual understanding.

Demonic Magic – The bread and butter of devils. Flexible, creative, and powerful in the right hands.

Holy & Light Magic – Lethal to devils, but also one of the most powerful forces in this world.

Elemental Magic – Fire, ice, wind, lightning—control over the natural elements, each with unique applications.

In short? Magic was essential.

If I wanted to survive and thrive in this world, I couldn't just rely on strength and intelligence.

I stretched, cracking my knuckles as I stepped through the school gates, the warm glow of the setting sun washing over Kuoh Town.

"Alright. Tonight, I officially start my magic grind."

With my 100X Multiplier, how long would it take to go from a complete beginner to an actual mage?

A day? A week?

I rolled my shoulders, smirking.

"If learning Japanese and calculus was this easy, how hard could magic possibly be?"

I paused.

A chill ran down my spine.

Then, narrowing my eyes, I muttered to myself:

"Wait… those sound like famous last words." 

——————————

I had barely stepped out of Kuoh Academy's front gates when I heard it—rushed footsteps closing in behind me.

"Three… two… one—"

"Yo, Malrik!"

There it is.

I turned just in time to see Issei Hyoudou skid to a stop beside me, panting slightly.

And, of course, he wasn't alone.

Lingering a few steps behind, whispering amongst themselves like conspiracy theorists uncovering a forbidden truth, were his ever-loyal perverted duo—Matsuda and Motohama.

Issei, however, wasn't whispering.

No, he was staring at me—wide-eyed, like I had just transformed into a Final Fantasy protagonist overnight.

"Dude," he blurted out, waving a hand at me like that explained anything. "Seriously, what happened?! You look like an anime protagonist!"

I smirked.

Couldn't pass up an opportunity like this.

"I made a wish to the great Oppai Dragon. Looks like he granted it."

For a full two seconds, Issei just stood there, blinking rapidly, trying to process what I just said.

Matsuda and Motohama exchanged equally confused glances, before Motohama dramatically adjusted his glasses.

"Wait… Oppai Dragon? That sounds… vaguely familiar…"

And just like that, Issei snapped out of his daze.

"Wait, what?! What great Oppai Dragon?! Why don't I know about this?!"

I laughed, brushing it off with a casual wave of my hand.

"Relax, Hyoudou. Let's just say I had a lucky day and leave it at that."

Issei squinted at me, clearly suspicious—but curiosity won over.

"Lucky day, huh?"

I nodded. "Yup. Anyway, wanna hang out sometime?"

For a second, Issei looked genuinely surprised.

Most people didn't casually invite Issei to hang out. Thanks to his… reputation, he was more often avoided than welcomed.

But here I was—the new "cool guy" on campus, casually extending a hand to him like it was the most normal thing in the world.

And it clicked instantly.

His expression brightened, his usual goofy energy returning full force.

"Yeah! Hell yeah, man! You seem like a chill dude. And finally, someone who gets it!"

Matsuda and Motohama nodded furiously in agreement.

"Yes! He understands!"

"We need more enlightened ones in our ranks!"

I sighed internally.

"Ah. So this is how I accidentally joined the pervert brigade."

Oh well. Could be worse.

With a final laugh, I patted Issei's shoulder.

"Cool. We'll figure something out soon."

As I walked away, I could already hear them whispering amongst themselves.

Matsuda: "Dude, he's like the final evolution of us!"

Motohama: "The perfect mix of chad energy and anime wisdom…"

Issei: "I have so many questions."

I smirked.

"Oh, you have no idea how many answers I'm not giving you yet."

Back home, I sat at my desk, laptop open, scrolling through a suspiciously detailed magic forum that I may or may not have stumbled upon through… questionable means.

I exhaled, tapping my fingers against the keyboard.

"Alright."

My eyes scanned through a breakdown of basic demonic magic theory.

If this world worked like the DxD lore said it did, then magic should be as much about imagination and intent as it was about raw power.

I leaned back in my chair, cracking my knuckles.

"Let's put my cheat system to the test." 

From what I read, most beginner magicians spent weeks studying magic circles—painstakingly memorizing runes, practicing linework, and struggling for days before they could even manage a faint spark of energy.

Me?

I glanced at the diagram once.

And that was all it took.

[Ding~] 100X Multiplier Activated!

In an instant, my mind auto-downloaded an entire magic textbook.

The structure. The placement of sigils. The hidden meaning behind every intricate line.

I understood everything.

"Alright. Moment of truth."

I grabbed a blank sheet of paper, casually drew a magic circle, and—

FWOOM.

The room lit up instantly as a perfectly formed magic circle hovered above the page, crackling with raw mana.

No resistance.

No strain.

No hesitation.

Just pure, instinctual mastery.

Mana flowed through my body effortlessly, responding to my will as if I had been casting spells my entire life.

I sat back, staring at the floating sigils, their soft glow reflecting in my eyes.

Then, slowly—I grinned.

"Magic unlocked on the first try? Someone pinch me, I'm officially OP."

With a flick of my fingers, the magic circle vanished in a brief shimmer of light.

Now… what's next?

Aika had potential. Training her might be interesting—I could turn a side character into something much greater.

Rias and Sona were already curious. I needed to keep playing the long game.

I smirked, my gaze drifting toward the night sky outside my window.

"Kuoh Academy has no idea what's about to hit it."

Magic prodigy.

Instant genius.

Billionaire overnight—

My grin widened.

"Maybe it's finally time for me to enjoy being the main character."