Reincarnated in DxD With the 100X System

Afternoon classes.

The part of the day where half the students mentally checked out—some barely listening, others counting down the minutes until the final bell like prisoners waiting for parole.

But for me?

It was time to test my cheat system again.

I lazily flipped open my history textbook, letting my eyes skim the pages full of names, dates, and political conflicts.

And the moment I read something—

[Ding~] 100x Multiplier Activated!

Like magic, every word, every tiny historical detail locked into my brain with laser precision.

I wasn't just memorizing the facts—I understood them. Cause. Effect. Significance.

It was as if my mind had turned into a perfectly organized Wikipedia page, complete with cross-references, citations, and absolute clarity.

"Damn. This is overpowered."

By the time the teacher asked the next question, I already had the answer before he even finished speaking.

"Alright, class. Can anyone tell me what led to the collapse of the Tokugawa shogunate?"

A long, awkward silence.

I glanced around.

Half the class looked like they had been hit with a status effect called "Perpetual Confusion."

A few students desperately avoided eye contact, silently praying the teacher wouldn't call on them.

"Welp. Guess I'll carry this team."

I sighed internally and casually raised my hand.

The teacher looked visibly relieved.

"Van-kun?"

I leaned back slightly, answering as if I had just casually read the morning news.

"The Boshin War, initiated in 1868. A direct result of growing dissatisfaction with shogunate rule and the increasing influence of Western powers—especially after Commodore Perry's arrival in 1853. The Meiji Restoration marked the official transition of power, leading to the modernization of Japan."

Silence.

The teacher blinked.

The entire class turned to stare at me like I had just spoken in an ancient, forbidden dialect.

"That's… correct," the teacher said slowly, his tone laced with confusion. "And very well explained. Have you… been studying ahead?"

I shrugged, offering an easygoing smile.

"Let's just say I had an overnight inspiration."

The teacher nodded, impressed.

Meanwhile, the murmurs started.

"Wait… wasn't he just normal before?"

"Dude just explained history like a college professor."

"Did we get a new genius student or something?!"

I mentally smirked.

"If they only knew how literally true that was."

Next stop: chemistry lab.

The day's project? Mixing specific compounds to create a stable reaction.

For most students? A confusing mess of trial and error, sprinkled with a high probability of failure.

For me?

[Ding~] 100x Multiplier Activated!

I scanned the periodic table once—and that was all it took.

Atomic weights? Memorized.

Reactivity levels? Understood.

Chemical bonding patterns? Burned into my brain like I had spent years in a lab.

"This is kinda ridiculous."

Casually grabbing the necessary compounds, I measured everything with pinpoint precision, mixed the solution, and—

Boom. Flawless reaction.

The mixture shifted colors exactly as expected, no mistakes, no hesitation.

Across the room, students were struggling, adjusting measurements, or trying to remember if "eyeballing it" counted as science.

Meanwhile, my lab partner—who had been mentally preparing for a small explosion—just stared at our perfect result in disbelief.

"...Dude, what?"

A shadow loomed over us.

I glanced up to see the teacher approaching, his sharp gaze fixating on my beaker like it had personally offended him.

He looked at the flawless solution. Then at me. Then back at the solution.

"Van-kun… have you been secretly studying chemistry all this time?"

I gave a casual shrug, keeping my expression deliberately comedic.

"I had an overnight inspiration. Let's just say I discovered the chemistry of self-improvement."

The class burst into laughter.

Even the teacher cracked a grin, shaking his head. "Smooth recovery."

I leaned back slightly, smirking.

"Guess I'm a natural at being a genius now." 

By the end of the period, my reputation was officially cemented.

History? Speedrun.

Chemistry? Effortless.

Math? Solved before the teacher even finished explaining.

And the best part?

No one had a single clue how I had gone from "average student" to an academic powerhouse overnight.

I leaned back in my chair, casually stretching as the confused whispers buzzed around me.

"Keep guessing, Kuoh. You're only scratching the surface."

The sharp chime signaled the end of my first day as a transformed student.

And looking back?

✔ Shocked my classmates with my sudden glow-up.

✔ Showed off my cheat-tier intellect in class.

✔ Caught the attention of Rias and Sona.

✔ Started casually flirting with Aika Kiryuu.

Not bad for a single day.

But if I wanted to truly dominate the supernatural side of DxD, I needed to focus on something way more important than just looking good and bulldozing the school's academic curve.

Magic.

I let my gaze drift across the classroom, landing on Aika Kiryuu as she laughed with a group of friends on her way out.

Sharp. Witty. Quick on the uptake.

In the original DxD story? She was just a side character, someone who never got involved in supernatural affairs.

But with the right training?

I could turn her into something far greater.

"First, though… I need to actually understand magic myself."

Time to take the next step.