Highschool DxD : Actually Satan

Extra large chapter..

Also I'll warn you this story is slow paced but it will start picking momentum from next chapter

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Two days later, Leo sat in his classroom, his posture the picture-perfect ideal of a diligent student.

His back straight, his gaze unwavering, and his eyes seemingly glued to the blackboard.

The teacher droned on about chemical equations, scrawling formulas on the board, but for Leo, it was all white noise.

His mind was as empty as a void, not registering a single word being spoken.

He had mastered the art of awakened sleep.

On the surface, he appeared deeply engrossed in the lesson, the model student, but in reality, his consciousness was focused elsewhere.

Over the past two days, Leo had been steadily working on his Informational Parasite skill.

While two day ago he couldn't yet wield it without contact, incremental changes in the informational essence of his classmates had been a good practice dummy.

His targets sat far from him, carefully chosen to avoid suspicion.

A lanky boy near the window, a girl fiddling with her pen two rows behind him—both of them seemed ordinary, unaware of what was happening.

They weren't random, though.

He had intentionally picked people known for their intelligence, aiming to enhance fragments of their cognitive ability.

It wasn't a full-blown change yet, but small edits: nudging their thought patterns, redirecting their focus, excess potential , and gradually amplifying his own intelligence in return by stufying their composition.

Leo's inner monologue hummed with sharp focus.

Two meters. That's the range right now. It's still limited. If I push harder… maybe I can extend it to three meters. Four meters. Damn it, why do I still need contact for complete rewrites?

He had successfully altered a few classmates who'd been in close proximity earlier—simple edits, nothing drastic.

A girl who'd been constantly interrupting others during group work now hesitated before speaking, her sharp tongue dulled just enough.

A boy who'd been failing miserably in math had suddenly started improving slowly.

All experiments, small ripples in their essence, but still underwhelming compared to the potential Leo sought.

This skill is too slow, he thought. If I can't even tweak something at range, what's the combat application of it? I need to level up fast.

He focused on the boy by the window again.

Leo's mental threads reached toward him like an invisible web, feeling out the boundaries of his information.

It was like brushing against a canvas and finding the threads in the weave.

Slowly, carefully, Leo tugged.

It was subtle—shaving away unnecessary distractions, redirecting mental resources, and funneling a whisper of the boy's latent potential into himself.

And it worked.

Just slightly.

He felt a twinge in his own mind, like the faintest drop of clarity had splashed into his thoughts.

His head buzzed lightly, a pleasant sensation, as if his brain was stretching itself.

The boy, meanwhile, yawned and scratched his head, oblivious.

Another success. …

He pushed harder, his focus narrowing, trying to stretch the skill further.

The threads connecting him to the boy began to fray, vibrating under the strain. His brain throbbed slightly, a warning.

It is to note that even at this range if leo could kill him by messing up his canvas but precision manipulation required efforts.

Leo sighed internally, releasing the thread before it snapped entirely. For now, his experiments had to remain small-scale.

But he was learning—every attempt taught him more about the mechanics of the skill.

The edits he was making were getting cleaner, more precise.

Soon, he'd be able to push past these limitations.

The teacher's voice interrupted his thoughts.

"Leo, could you solve the next equation?"

Snapped out of his trance, Leo blinked and stood up, his face perfectly calm.

He had no idea what was on the board.

He hadn't been listening at all.

But his enhanced intellect and pre avilable knowledge in his brain carried him through.

Scanning the board for barely a second, he grasped its solution almost instantly and rattled off the answer with confident ease.

"Correct," the teacher said, slightly impressed.

---

Leo sat at his usual spot on the rooftop, leaning against the railing as the cool breeze rustled his hair.

His lunchbox remained untouched by his side, its purpose as obsolete as his need for food.

Ever since gaining parasitic immortality and the informational skills, the necessity—and even the joy—of eating had faded from his life.

It was one of the many small sacrifices he had made, trading away humanity's simple pleasuresand gaining power by modifying his own body.

He was lost in thought, staring blankly at the horizon, when the door to the rooftop creaked open.

Turning his head slightly, he saw Koneko step out.

She was quiet, as always, her small frame and feline demeanor making her presence ghostly.

She glanced at him briefly but said nothing.

Leo smiled faintly and raised a hand in a lazy wave.

He didn't expect her to respond—Koneko was a recluse, a girl of few words who preferred silence over conversation.

That suited Leo just fine.

They were far too messy, far too interconnected far too fast with the world he was beginning to entangle himself in.

She took a seat on the opposite side of the rooftop, opening her own lunchbox.

Leo didn't move to speak.

He respected her silence and didn't want to invite her curiosity—or anyone else's.

As he leaned back against the railing, the system's interface flickered into his mind.

[Mission: Laying Your Claim.]

It was the First stage of his story tree, and Leo knew it was important.

[Objective: Announce your presence as the true Satan of this world.]

He skimmed through the details again. There were options—there were always options—but none of them were simple.

The system outlined two primary approaches:

[ 1. A Subtle Claim: Make your presence known to a small, contained group of supernaturals. Announce yourself as the Satan without triggering widespread chaos. This would provide moderate rewards, enough to grow stronger but not enough to make a significant impact.

2. A Grand Declaration: March into the heart of the Underworld—into Lucifer's domain—and lay your claim in front of the four current Satan leaders. Threaten their fragile system with destruction, offer them a timeline to fix the Underworld's issues, and act as if you're a higher power offering an ultimatum. This would yield far greater rewards but would draw all attention to you, putting you in direct conflict with the Devil factions and potentially everyone tied to them. ]

Leo let out a frustrated sigh. The system was pushing him toward the risky option, dangling those tempting rewards like a carrot on a stick.

Sure, he could do it small-scale, keep it contained, but where was the fun—or the power—in that? The Underworld was a mess, with political corruption, infighting, and fractured loyalties that could be easily exploited.

His best option for long-term influence was to target the core of their system, but the risks were monumental as it could spiral out beyond hiw controls and the next thing he will have to do at that point is something the german guy with funny mustache would love.

Koneko glanced at him briefly, probably sensing his internal turmoil, but didn't say a word.

---

Leo sat beside Koneko, quietly observing her as she munched on the cookie cookie, seemingly oblivious to his presence.

His eyes flickered briefly, glowing a faint, eerie yellow.

A faint pulse of energy surged within him as the world around him shifted in his perception.

Everything physical—the rooftop, the sky, the school below—faded into the background, replaced by intricate layers of data.

The fabric of reality revealed itself as a lattice of quantum interactions.

Numbers and equations spiraled before him, visualizing gluon interactions holding matter together.

The Higgs field appeared as ethereal strands, quantifying the mass of every particle within his vision.

What fascinated Leo the most was how seamlessly this information coalesced into what everyone perceived as reality, yet he now saw it for what it truly was: raw, manipulable data.

This shift in perception was the result of the only self-modification Leo had dared attempt using the Informational Parasite Skill.

He had parasitized his own information, rerouting external energy to transform his left eye into a conduit for analyzing the information structure of the universe.

The process had been agonizing, every cell in his eye screaming as it was rewritten, forcing Leo to limit the modification to one eye for now.

Despite the pain, the result was worth it.

Turning his enhanced vision toward Koneko, Leo noticed something intriguing.

Her data was fundamentally different from that of normal humans.

Multiple external layers of information swirled around her, vibrant and dense, hinting at a complexity far beyond the mundane.

Animalistic traits flared within her core, almost as if her essence was intertwined with something well animalistic.

Which given she was basically cat given human body it made sense.

But what truly caught his attention was the magic within her or more specefically the evil piece.

But more important to note was just plain old magic when present in large amounts.

Unlike physical particles, which followed predictable quantum interactions, magic carried an entirely unique signature.

It warped the density of her "mass of information," an abstract measure Leo had developed to quantify the complexity and weight of a being's essence.

Magic, he realized, wasn't just energy—it existed as information flowing against the grain of time, reversing its flow while remaining integrated with the physical world.

Leo found this utterly fascinating.

However, he couldn't interact with it yet.

He didn't fully understand how to access or manipulate this reversed flow of information.

Magic,is like data folded over itself in ways it seems magical in itself for it to exist.

Koneko glanced briefly at him, her golden eyes narrowing slightly as though sensing something was amiss.

But she quickly returned to her cookie, dismissing his stare as unimportant.

Leo sighed in relief and leaned back.

She hadn't noticed his observation yet, but this encounter gave him valuable insight.

And oh boy was it an insight...

Leo's eye looked at the carefree Koneko as she quietly munched on her cookie, completely unaware of the sheer cringe-fest that was her devilified physiology.

The moment he looked past the surface with his parasitic modifications, he nearly recoiled.

It wasn't just bad—it was straight-up butchery.

Her nekomata side was elegant and naturally harmonious, something primal yet beautiful.

And then the devil bullshit came along, slapped on like someone took a paint bucket to the Mona Lisa.

Fucking Ajuka,Leo thought, half laughing, half disgusted. Genius my ass.

The guy's a toddler playing with quantum crayons.

Don't get him wrong—the devil pieces were an impressive bit of work.

Ajuka had managed to force supernatural traits onto beings without even understanding the fucking superluminal magic particles he was working with.

Mana wasn't energy—it was a particle, moving faster than light, literally reversing time for itself and all the particles around it.

The evil piece shit was quantum insanity, and Ajuka slapped it together like he was mixing cement.

Leo's enhanced vision showed just how bad it was.

The mana interacting with Koneko's nekomata "core" wasn't just a mess—it was cruel.

The whole thing reeked of informational violence.

He didn't even know if such a word existed.

Her existence, her very essence, had been rewritten in a way that, while functional, was agonizing to look at.

The forced melding of traits didn't respect her body, her spirit, or the unique flow of her nekomata heritage.

It's like someone built a Ferrari and decided, 'Hey, let's weld a train engine into this bitch and call it a day,' Leo thought , his yellow eye twitching.

And the worst part? No one else would even notice.

Koneko, the devils, the fucking supernatural big shots—they were all oblivious.

They couldn't see what Leo saw.

They didn't know that mana was time-reversing particles.

They didn't know the reincarnated devils were walking Informational crimes, held together by duct tape plus thoughts and prayers.

Quite literally.

The evil pieces relied on the master-servant bond to keep the whole thing from falling apart.

Without that external link stabilizing the process, the entire system would probably collapse in on itself like a dying star given the master can renew the code on the layer of devilification that decays.

The evil pieces essentially forced a new layer of information over someone's existing physiology, creating a devilification effect.

But here's the kicker—it didn't actually bother to integrate properly if one wasn't naturally compatible.

Instead, it pinned itself into place using the mental and magical connection to the master as a stabilizer.

The bond acted like some kind of janky scaffold and backup, constantly holding the pieces together because the devilification wasn't strong enough to stand on its own.

The quantum framework of incompatible reincarnated devils was so fundamentally unstable it could only function because of this external crutch if things start to get bad.

The native magic particles of the original body were essentially bullied into holding the new physiology in place.

Without the master's connection , the system would crumble like a house of cards if the person devilified isn't compatible with devil physiology naturally.

It's like someone built a fucking skyscraper, but instead of using steel beams, they used spaghetti and hoped no one would notice,

And the spaghetti only holds because the chef's praying real hard.

This wasn't just bad design—it was virtual nonsense manifesting in the quantum realm.

The evil pieces essentially projected a false construct of devil physiology over the original body.

The problem? It wasn't real.

The devil traits didn't truly merge with the host; they were just pinned there, floating like a ghostly overlay.

It was all a facade, held together by belief, loyalty, and the master-servant link.

The sheer absurdity of it made Leo's eye twitch.

Ajuka Beelzebub, hailed as a genius, had created this half-assed system without even realizing how fundamentally unstable it was or maybe he did.

Leo doesn't know.

And yet, despite how flawed it was, it somehow worked.

The reincarnated devils walked, talked, and wielded magic like the system wasn't a disaster waiting to happen.

But Leo knew better.

He saw the cracks in the foundation present in Koneko, the way the magic particles strained to maintain the illusion.

One wrong move, one severed bond, and the whole thing could fall apart resulting in a clusterfuck of problems.

Which do emerge in strays..

Anyways lets move on.

Leo finally managed to calm himself, his frustration with the devil physiology mess fading enough for him to focus on something else—or someone else. Sitting next to him, Koneko continued to munch on her cookie, her silence as impenetrable as ever. Without really thinking it through, he turned to her and asked, "What are you doing next Sunday?"

Koneko stopped mid-bite and turned her head toward him, her expression unreadable but her stare sharp enough to cut.

The silence that followed wasn't a neutral one—it was a heavy, judging silence that made it abundantly clear what she thought of his sudden question.

If looks could talk, hers would've been screaming,

You're filth. Absolute, irredeemable filth.

Leo could almost feel the weight of her unspoken accusations.

She thinks I'm into lolis. Fuck.

He raised a hand defensively, shaking his head. "No, no, no," he said, as if trying to physically block her thoughts.

"I'm not romantically interested in you. You don't even remotely fit my criteria." His eyes flicked over her frame briefly—flat, small, clearly younger-looking than she actually was. "I mean, obviously. You're not my type."

Koneko's glare intensified, her eyes narrowing just enough to make him sweat.

Leo sighed, rubbing the back of his neck as he tried to recover from the self-dug pit he'd fallen into. "Look, I'm normal, okay? A regular person. And this isn't… whatever you think it is. Ever since I was a kid, I've just been bad at making friends. I had a few, but honestly, they weren't great. You know the kind of friends who talk too much and just never shut the fuck up? Yeah, those. Anyway, I was thinking maybe… maybe we could be considered friends? Like, we could hang out or something. Do normal friend stuff."

Koneko continued to stare at him, her expression unchanging.

She didn't give him even the slightest sign of acknowledgment, let alone agreement, and Leo started to feel the need to fill the silence with more justification.

"Not weird stuff," he clarified quickly. "Just… normal. Casual. Whatever."

In reality, though, this whole "let's be friends" thing was mostly a cover.

Sure, Leo genuinely appreciated the quiet, companionable silence she brought to the table—sitting next to Koneko for the past few days without having to endure mind-numbing small talk had been the best friend-like experience of his life—but that wasn't his main goal.

The real reason was the guilt.

Every time Leo looked at her, the absurd patchwork of her devil and nekomata physiology stared back at him like an insult to nature.

The evil piece system that had turned her into a devil was effective, sure, but the way it melded with her nekomata origins was… horrifying. Sloppy didn't even begin to cover it.

And Koneko didn't deserve that. She hadn't asked to become this stitched-together mess.

Leo figured that if he could get close enough, maybe he could use the time together to tweak and correct her evil piece.

Even if it was just a small adjustment, it might make things easier for her.

He hadn't quite figured out how to do it yet, but the silent camaraderie they shared gave him the perfect excuse to keep trying.

For now, though, he waited, awkwardly enduring her glare.

Koneko didn't respond to his offer of friendship, but she didn't leave either. She simply went back to her cookie, ignoring him as if his existence didn't matter.

After a few moments of silence, the white-haired girl finally spoke, her voice soft and measured.

"Okay, let's be friends," she said, almost as if testing the words for herself.

Leo blinked, mildly surprised.

He hadn't expected her to actually agree, let alone acknowledge his rambling.

Before he could respond, she continued, still speaking quietly but with a tone that carried more weight than he anticipated. "I'm Koneko," she introduced herself simply, her amber eyes meeting his for a brief second before flicking away again. "And… I'll probably not be able to go with you on Sunday. But…"

She hesitated for a moment, as if weighing her next words carefully, then shrugged. "Maybe we could go somewhere on Monday."

" Skip school or something. I don't know."

Leo raised a brow at that, not entirely sure if she was joking.

Koneko, the stoic and silent recluse, suggesting they ditch school? That was… unexpected.

"I just hate math class," she admitted, her tone flat but tinged with a faint hint of exasperation. "And I'll do anything to skip it."

She glanced at him again, this time with a look that almost seemed curious. "Last I checked, you skip school sometimes too. So… maybe you can help me or something."

The confession caught Leo off guard.

This was, without a doubt, the most Koneko had ever said in a single conversation.

It was almost out of character for her—completely out of character, actually.

She was usually so quiet, so reserved, that this sudden willingness to engage felt strange.

And yet, he could understand why.

Koneko probably enjoyed his company, even if she'd never say it outright.

Unlike others, Leo didn't bother her with endless questions or force her into conversations she clearly didn't want to have.

He was respectful of her silence, and when he did talk, it wasn't to fill the air with meaningless chatter.

Maybe that was why she felt comfortable enough to open up, even if just a little.

For his part, Leo simply nodded. "Sure. Monday works," he said, keeping his voice light and nonchalant, as if this entire interaction wasn't completely surprising.

He wasn't going to ruin the moment by making a big deal out of it.

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Stones and Reviews please