Sēx System: Destroying DxD

In the cosmos existed a void.

This void was full of iridescent hues clashing with each other. One could describe the view as being similar to the view from a kaleidoscope.

In this void, there was a terrifying creature.

Were Tatsuya to see this creature he would jump in excitement.

A massive hundred-meter western dragon with a horn on its snout with two sets of wings was shuttling through the colourful hues with ease. Its movements rip apart in the soundless void. Its actions seem to taint the serene nature of this endless void.

The red dragon was flapping its wing with joy when all of a sudden it froze. It turned its head around for a short while before stopping its flight.

"Invader?"

The massive dragon seemed to be frowning as it shook his head.

The ripples in the void were clear for it to feel.

"Untraceable source? Perhaps…"

"Anomaly!?"

A terrifying thought emerged in its head.

The mere mention of that term caused it, the strongest being in this world, to shiver from head to toe.

Long long ago, from the moment it first opened its eyes, it had a short dream. A blurry figure patted its head with warmth and warned it of two things.

The first is Chaos.

The second is the Anomaly.

The Great Dragon of Dreams and the Great Dragon of Infinity were born to control the Beast of Apocalypse, 666.

After Chaos came Order.

Yet the blurry figure was clear with its warning.

The Anomaly had to be eradicated as soon as possible, should it be allowed to roam unhindered…

The world, the void and the cosmos, all shall fracture.

Fractured and destroyed.

After that, the Great Dragon of Dreams never saw that figure, the Creator, again.

The Dragon restlessly circled the void.

It had to find the Anomaly.

…

Elsewhere.

In a small bustling town, there was a dark alleyway.

A man and a woman emerged from it in the dark of the night.

The man was 188 cm tall and had a robust physique. He was wearing a black gym compression with baggy white pants. His muscular stature clung to his clothes, threatening to rip the fabric apart. His face was sharp with clear-cut features and bright eyes. His long black hair fell loosely behind him. Even models or actors would find themselves inferior standing next to him.

The woman next to him appeared to be a high schooler.

She was equally beautiful with fair soft features. Her red hair fell to her waist as she walked around with a curious expression. Her bright amethyst eyes shone glamourously.

"This does not feel any different than my world."

"Is that so?" The man walked along the bright road with a somber expression.

Numerous gazes landed on the pair, some out of fascination and some out of jealousy. No matter what, the couple looked out of the world. Some girls even took a few pictures covertly.

Amasawa noted all of this and her smile remained the same. Inwardly she was wondering just how different this world could be. Tatsuya seemed quite different, unlike his carefree self in her world.

Amasawa guessed correctly.

Tatsuya was not pleased.

You're telling me I'm in DxD? A week before the plot starts?

[Yes, since we've entered the world I have already analysed the source essence. From your memories it is clear that this Kuoh Town which houses the Kuoh Academy belongs to the anime you call Highschool of DxD.]

Tatsuya sighed.

His rusty mind began to rationalize his future actions.

DxD is not exactly bad. With my current powers I…

Tatsuya's eyes turned frosty.

I still can't compete with the true powerhouses of this world like Sirzech and the Heavenly Dragons. I won't even consider Great Red and Ophis, they'll kill me in the blink of an eye. Ban's regeneration makes me functionally immortal so I should be safe for most of the part. Only powers like Destruction or the hax owned by those dragons or beings could actually kill me. This makes things troublesome. I need to get a good grasp of how Destruction and similar powers work.

Could Rias kill me?

Tatsuya stopped at the point and laughed.

Kaguya, how am I supposed to grow stronger? Is it training the usual way or the spins using World Essence?

Kaguya remained silent and an ominous feeling nudged at Tatsuya's heart. He let out a meaningful chuckle.

[It's going to be hard. I have exhausted most of my essence to give you as many skills as I could in the first world. Any dangerous movements like extracting multiple skills through bridges will be detected by the Heavenly Spirit. At most, we can afford three spins, not to mention I'll have zero control over the skills extracted. They could either be useful or utterly useless. Not to mention the mere act of extracting skills will be ten times more difficult. You'll need at least 2000 World Essence for a spin.]

Tatsuya listened silently.

[Don't feel disappointed, I've done my best to enhance you as much as I can. It was not easy to make your physical flesh nearly indestructible. Even in this world, you're not weak at all. As long as you tread cautiously there should be no problem. If it weren't for the fact I was scared that establishing stronger bridges would alert the Heavens Domain I would've given you stronger abilities.]

I see…

Tatsuya smiled as he reached his destination. He entered the ordinary-looking house with Amasawa and settled down. The System had prepared his identity and residence in advance. Such actions were necessary or his abnormalities could be detected.

"Is this our new home?" Amasawa looked around the house in wonder, how did he have the keys prepared for a house in a world he had just arrived in?

Another one of those magical powers?

"Yeah," Tatsuya nodded, "Oh, by the way, I've crafted identities for us. We're siblings on paper okay? You're not Ichika Amasawa anymore but Ichika Yamamoto."

Tatsuya sat down on the sofa.

"Eh? Uhm so what should I call you then?" She let out a seductive smile, "Onii-chan~?" Her sensual voice drifted into his ears.

Tatsuya smiled in response as his pants began to bulge. Amasawa's smile brightened as she dropped to her knees and crawled towards him, swaying her hips like a cat.

The sight aroused Tatsuya.

He rubbed his erection through his pants and gave Amasawa a suggestive gesture. She came closer in response and pulled his cock out of his pants. His bulging erection landed right next to her face, unable to fit in her petite palms. The heat radiating from the rock-hard cock was menacing.

The size more so.

She could barely fit both hands on it.

The veins pulsed against her soft skin and Amasawa felt her heart beat faster. The smell was intoxicating, no matter how she tried to clear her mind it continued to infiltrate her senses.

Another ability!

A professional like Amasawa could declare instantly. The control she had over her body was inhumane. Any foreign infiltration could be almost instantly discovered.

The hungry cock twitched in her hands and she began to pump it.

But much to her surprise Tatsuya looked at her impassively and she wondered what she had done wrong.

It took her only a second to understand as she stopped pumping her hands. She leaned over and placed her lips above the cockhead. Her lips parted as spit began to dribble out of her mouth.

It fell onto his cock and she began to slather it. She repeatedly spat on his cock till it was completely coated with her spit. She began to pump him once again with greater vigour. The slimy cock continued to make pch pch sounds as the enthusiastic Amasawa continued her duty.

All Whiteroom students were incredibly adaptable.

Tatsuya was lost in pleasure as he closed his eyes and enjoyed the service of his now little 'sister'.

Kaguya materialised behind him.

She wrapped her hands around his neck and whispered, "I've prepared enrollment for both you and her in Kuoh Academy."

Tatsuya wasn't pleased.

But he didn't retort. She must have her reasons for doing so and he had his own suspicions. Ever since he had absorbed Ayanokoji's knowledge he felt his mind working faster than usual.

It was an absolutely correct decision to devour him.

"I know you don't like being ordered around but listen. Growing traditionally is an okay route but you don't have that avenue. Should you have obtained Ayanokoji's adaptability I would've left you to your own devices. Unfortunately, your talent is decent at best. Even if you grow it would take too long to reach the level of Dragon of Dreams and Dragon of Infinity, if the Heavenly Spirit detects something and wakes up we'll be in danger. Alternatively, the spins themselves don't guarantee anything. Perhaps you can get something that'll boost your strength but the possibility is slim at best. While I'll still advise you to train traditionally I can help boost that progress through World Essence. And by now…"

She leaned in closer.

"...You should know how World Essence is obtained."

Tatsuya kept his eyes closed as he felt his release build-up. He extended his hand and roughly grasped her head.

"Open your mouth."

Ichika was stunned but she immediately opened her cherry lips and thick ropes of cum began shooting inside her mouth. However, it didn't end there. Tatsuya increased the pressure of his hand and Ichika was forced to swallow his member.

She felt her lips stretch as the monster plunged itself inside her. She controlled her gag reflex and her tongue began licking the base of his cock. She did her best to control her reactions to please Tatsuya even as tears streamed down her face. It wasn't that she was crying out of pain but a bodily response. Ichika had faced much worse torture in the Whiteroom. She began bobbing her head and sucked his cock with all her strength.

Tatsuya was pleased with her.

You want me to mess with the characters? Is that it?

"Don't act like that, is that not your own wish, you twisted human?" Kaguya would never forget the reason she chose Adrian Frost of all humans.

Tatsuya's expression turned blank before a sickening smile surfaced. Even the devil itself would shudder looking at his smile.

As long as I don't kill Issei, I can do anything… Is that correct?

"Correct," Kaguya smiled, "The stronger the Heavenly Being the deeper its sleep. In fact, most Heavenly Spirits above the Third Tier are self-automated, meaning even if they are sleeping they can govern the world. Unfortunately, Pseudo Heavenly Spirits lack that skill. As long as you don't cause too much of a disturbance early on we'll be fine. Once I've sufficiently corroded the sleeping Spirit you can let loose. For that, you have to ruin this world as much as you can bit by bit."

I understand. Tatsuya nodded as he came inside Ichika's mouth.

He threw her towards the sofa and mounted her, pushing his cock inside her mouth once again.

He began thrusting his hips roughly, his balls smacking against her chin. Amasawa could only endure the abuse as her mouth was violated. She was prepared for this the moment she saw Ibuki, the toilet, for the first time.

Their relationship might seem amicable at first glance but Amasawa was all but clear, a single mishap and she'd find herself becoming the new toilet.

Even as her eyes reddened she did her best to pleasure him.

Soon, Tatsuya came again and filled her mouth to the brim with hot cum.

Satisfied, he pulled his cock out of her mouth and cast [Clean].

"Here," He threw her a phone, "It has my contact in it. The Internet should work as well. Rest up, I'll brief you about some things in the morning."

"Okay, Onii-chan~"

Tatsuya shook his head with a wry smile.

She was enjoying this too much.

Once Amasawa was gone he too went to sleep.

…

A week passed by in the blink of an eye.

Amasawa along with Tatsuya headed towards Kuoh Academy with light steps. Amasawa still had a hard time calming herself down.

Devils, Yokai, Dragons and whatnot.

This was a fantasy world!

A fantasy world through and through!

But with excitement came worry.

Just how strong was Tatsuya compared to these magical beings? While Amasawa had her doubts she kept them to herself. The strength he had shown in her world was not too exaggerated, only his speed was the thing she found most astounding.

As for slaughtering a bunch of people and punching through metals, the Dragons should be able to do much more than that right?

Her thoughts were scattered as they reached the gate of Kuoh Academy.

…

Streams of students could be seen entering the gate with excited expressions.

Especially the boys considering Kuoh Academy had just turned Co-Ed. Until before it was a girls-only school.

But these boys began grinding their teeth in frustration. Pure hatred lurked in their eyes as they laid their gazes on the pair of approaching figures.

The male was tall, extremely so. He stood out like a swan amongst ducks. Where the average height of Japanese male high schoolers was around 165-175 cm his 188 cm tall frame stood out extraordinarily.

And if that wasn't enough his bulging muscles added an intimidating effect. Barely did any guy show open hostility despite their hatred for this new ikemen.

Compared to the boys the girls were practically swooning. They were comparing him to the Prince of Kuoh, Kiba Yuuto. Though, the majority thought Kiba stood no chance, some timid girls were too intimidated by his figure and found him scary.

The girl beside him was equally attractive catching the attention of all the boys, becoming an even greater source of hatred towards the aloof male.

This odd couple was instantly noticed by two figures by the gate.

One had a slim figure with a petite frame. She had a bob cut with violet-purple eyes framed with square glasses, giving her a scholarly look. The strict expression on her face made her appear as a stern individual.

She was Sona Sitri.

The one behind her was completely opposite to her.

A young bespectacled woman with long straight black hair that extended down to her knees, with split bangs and heterochromic eyes, with a violet left eye and a light brown right eye. Her figure was quite voluptuous, attracting a lot of attention.

Her name was Tsubaki Shinra.

"Yamamoto Tatsuya, Yamamoto Ichika..." Sona mumbled as she remembered the information file from before. She had memorised the data of the new students beforehand.

Noble Devils like her had to keep a lookout for useful additions to their peerages. Especially considering the situation of her close friend. She was in dire need of help.

"The sister is quite interesting," Tsubaki remarked, her eyes glinting as she examined the pair. Tsubaki wouldn't deny the charm Tatsuya had. His aloof expression along with his handsome face was quite the lethal weapon. Not to mention the stark contrast between him and the rest of the male students.

Tsubaki shook her head in disappointment.

"You're right, I wonder how much potential she has. The mana fluctuations around her are quite blatant. It looks like she's a novice. A bishop piece should amplify her talent quite a bit. I'll talk about her to Rias later." Sona nodded in satisfaction before turning to Tatsuya.

A few seconds later she shook her head.

There was no unique feeling around Tatsuya. Either his sister was hiding her powers from him or he had no talent in the path of magic.

Soon, she became disinterested and scanned the rest of the students.

Tsubaki's gaze lingered on Tatsuya for a bit longer, proving to be a mistake as he turned his head and looked straight at her.

Tsubaki was startled.

Did he sense my gaze!?

She saw him nod at her with a small smile before continuing along. Only after he disappeared did she come back to her senses.

She looked at Sona who noticed nothing and revealed a troubled expression.

In the end, she shook her head and regained her serious expression, standing behind Sona like her assistant.

…

"Those two have been staring at us weirdly for a while." Ichika linked her hands behind her back and skipped along her steps.

"They're the Devils I talked about," Tatsuya said while looking around, his gaze finally resting on a short brown-haired boy looking around with a perverted gaze. "Don't worry about them. Remember what we talked about and don't resist. One of them should approach you soon."

"Ah, so that's why." Ichika suddenly understood why she was forced to sense Mana for a week straight.

The day after they arrived Tatsuya fed her a Mana Sensing Pill and told her to meditate and feel the elements in her surroundings.

To Ichika it was a fascinating process. She could sense various elements in the air and much to her surprise she could gather them around her.

For example, the elements of fire, the red particles, gathered around her easily, like children returning to their mother's embrace. Yet when she tried to pull in the water element particles they resisted fiercely.

That should mean she had an affinity for Fire Type Magic.

Casting magic was easier than she thought.

She could already form a fireball.

All she had to do was visualise the process.

It might sound easy but remember, Amasawa is an artificial genius of the Whiteroom. Her IQ is many times higher than the average human.

When she mentioned visualising a fireball she did not mean just thinking of the image of a fireball. She needed to strengthen and concentrate her control over the fire particles before condensing them into a smaller area. She then had to rub the particles together in a controlled manner to create a spark, an ignition. She had to do this simultaneously for hundreds of particles before a fireball was formed in her hands.

The process was excruciatingly exhausting.

Only someone like Amasawa could succeed on her first try.

And remember this is just the basic fireball spell. Her attack not only lacked power, but it was also devoid of speed. Should she try to throw it away she'd lose control and the particles would scatter, dispelling the fireball before it could do anything.

This wasn't her fault, she needed a proper magic system and guidance to go further.

Tatsuya hadn't expected her to do something like this.

He was once again astounded by the Whiteroom.

Tatsuya couldn't help but wonder what would happen if someone like Ayanokoji were to embark on a solo journey in DxD.

Nonetheless, Amasawa did not have to worry about receiving orthodox education about magic. According to his plan that would be unnecessary.

Both Tatsuya and Amasawa separated as they were in different classes.

________________________

Important Author Thoughts— Completely AU. Also, don't bitch about him going to Kuoh, it's not even going to be relevant in a few chapters.

I do NOT plan to follow canon for anyone worried.

I have a rough plan in mind. DxD is a fun world to write and as the story progresses the influence of Tatsuya's actions will snowball massively.

By the near-mid part of this arc, everything will be pure chaos. Please bear with the occasional info dumps in the following few chapters.

Of course, since the chapters are 3000 words each minimum this arc won't have a lot of chapters. I've decided to not do unnecessary stuff (looking at you dream realm) and focus purely on the story.

This shouldn't be a problem as I don't have to just go on a fuck spree like Volume 2, this world has enough strength and characters for it to be fun.

Update speed— 3 Chapters a Week usually Tuesday, Thursday, Saturday, depends on powerstones and the love you guys show.

Powerstone goals— An extra Chapter every thousand powerstones. I don't actually want to give extra chapters since I'm usually busy with college but if the story gets more than thousand ps you guys deserve it.

Also if you're curious about Tatsuya's overall strength... You'll be surprised... Because I certainly was.

For the abilities part— please check the character profile in Auxiliary.

And once again if you're someone who's skipped the World Background Auxiliary Chapter, just go read it. It's barely a thousand words and explains everything you need to know briefly. Don't blame me if you're confused in the future, the plot in this story is serious so you will miss out on enjoyment the others who do understand will have.

Lastly— I hope you all enjoy it. I'll do my best to write an interesting story moving forward <3

...

Read 15 Advanced Chapters— Patreon.com/AlmightySkyDxddy