I was Thrown into an Unfamiliar Manga

The pain lasted only a moment.

The moment that something boiling inside my body was completely released, I felt a strange sensation.
Should I call it the feeling of having a third eye?
Information I hadn’t been able to sense just moments ago began flowing into my brain through expanded perception and vision.

Is this the 'power I couldn't use' that Fuma-senpai was talking about?
Clenching and opening my glowing orange fist, I checked the condition of my entire body.
Somehow, I felt like I could do anything right now.

As if noticing my dramatic change, Ivan, standing across from me, muttered with interest.
“This is what they call Eastern mysticism, huh? That a mere brat who knew nothing could handle this much qi just by taking one tiny pill.”

I slowly walked toward Ivan, whose body was marked with scratches from his fight with Fuma-senpai.
“Ivan Romanov. I don’t know why you took a liking to me. Frankly, I don’t really want to know. But there’s one thing that became crystal clear when you laid a hand on your own daughter…”
Pointing a finger right at his face, I declared:

“It’s the fact that you’re a hopeless villain.”
Becoming this kind of man’s disciple wouldn’t lead to achieving anything great.
Especially in a world like a shounen manga that emphasizes friendship, effort, and victory.

“Kuh… kuhuhu…”
But hearing my words, Ivan chuckled as if he had just heard a great joke, his shoulders shaking.
“Pwahahahahahahahaha!”

Then, clutching his stomach, he burst into loud laughter like a man with air stuck in his lungs.
“And you say that with such a serious face, and all you can call me is a villain? That’s so cliché! It’s beyond cliché!”
Then, suddenly turning serious, he stared straight at me.
“Brat. Words like that are nothing more than excuses for the weak. The strong can do whatever they want. This world has always operated on the law of the jungle.”

Ivan growled like a beast.
“The weak are destined to be stripped of all rights and freedom by the strong. So if you really want to persuade me, there’s only one way.”
He pointed at himself.

“Defeat me right here.”
***
‘What the hell is happening right now?’

Fuma Yukika was inwardly shaken by how much more effective the Demon God Pill had been than she expected.
‘Was this really such an OP item?’—she couldn’t help but think.
The Demon God Pill was originally designed to stimulate one’s latent true qi and temporarily amplify the user’s available qi output.

Literally, it draws out qi from the deepest parts of the body—even the marrow—so after its effects wear off, you end up with a body weaker than an average person’s for several days. But in a crisis, it ~Nоvеl𝕚ght~ becomes a hidden trump card. That’s why every ninja of the Fuma clan always carries at least one with them.
But when Kim Yu-seong took the pill, something completely unexpected happened.
The enormous amount of extreme yang true qi he had accumulated over 17 years burst out like a cola bottle with Mentos dropped in.

Worried, she used her spirit eye to examine him—only to see that every single qi channel in his body had opened up at once, as if he had undergone some form of .
And yet, the massive amount of true qi, unable to find a direction, kept wafting from his body like a shimmering heat haze.
‘With his current state, Kim Yu-seong might actually be able to defeat Ivan.’

The effects of the Demon God Pill would last about five minutes.
It might sound absurdly short, but in the world of masters, that’s more than enough time to settle a match.
Fuma Yukika swallowed dryly, watching the legendary duel about to begin unfold before her eyes.

***
The one who moved first was Kim Yu-seong.
His movements were incomparably lighter than before.

His legs, wrapped in orange radiance, looked as if they were on fire.
He kicked off the ground, aiming a high kick at Ivan’s solid upper body.
Boom!!!

Ivan retaliated with a high kick of his own, but when their legs clashed midair, the one to bounce back was, surprisingly, Ivan.
‘What power…!’
Ivan’s eyes widened.

Ridiculous strength.
Ivan clearly had the advantage in muscle mass and weight class, and until just moments ago, Kim Yu-seong had only shown physical ability slightly below or equal to his own.
But now the roles were not just reversed—the power balance was overwhelmingly in Kim’s favor.

His leg thrown back, Ivan quickly regained his stance and shifted position.
‘Лев императора’
The Emperor’s Lion.

Among the five martial styles Ivan had self-taught, this one had the highest killing power.
He changed the shape of his hands into hooks.
To replicate a lion’s claws with immense pinching force.

“Hup!”
He aimed for Kim’s one known weakness—his speed, which couldn’t match his newfound brute strength.
Determined, Ivan struck the ground and swung both hands at a speed Kim shouldn’t be able to react to.

Crunch!
‘What the—!’
But the one who got hurt wasn’t Kim Yu-seong—it was Ivan’s fingers.

Likely compound fractures.
Even though it was just human skin, Kim Yu-seong’s body was now as hard as diamond.
It seemed to be a result of the overwhelming yang energy radiating like a shimmering mirage from his skin.

While Ivan hesitated in shock, Kim Yu-seong headbutted him right in the face.
“Kghak!”
Ivan’s nose bone cracked, blood splashing everywhere.

Panicking, he tried to back away—but Kim Yu-seong wasn’t dumb enough to let an enemy go once they were in range.
“Clench your teeth.”
Unless you want to lose them.

“UOOOOOOOOOOOOOOOH!!”
A punch rush exploded with a battle cry that seemed to erupt from deep inside his lungs.
With his fingers fractured, Ivan couldn’t even make a proper fist and was forced to take the barrage unguarded. He began to regret it all too late.

‘Dammit! If only I’d used qi from the start!’
He had underestimated him.
If he had fought seriously from the beginning, he wouldn’t have ended up in such a pathetic state.

And then, a horrifying realization struck him.
‘I’m going to lose? Me? Not to Fuma Kotaro, my lifelong rival—but to some random high school kid?’
There could be no greater humiliation.

As his vision blurred under the endless barrage, Ivan grit his teeth.
If he couldn’t use his fists, he’d use the edge of his hands. If he didn’t have teeth, he’d fight with his gums.
He summoned blue qi from both hands.

‘Грифон императора’
The Emperor’s Griffon.
A mythical beast that symbolized kingship, born from the union of the lion—the king of land—and the eagle—the king of sky.

He swung both arms with force.
Crack!
But due to the qi radiating from Kim’s entire body, his senses were now heightened—he blocked the supposedly sure-hit attack effortlessly.

Ivan, now covered in bruises from head to toe due to the endless punch rush, glared with venomous eyes.
But Kim Yu-seong, merciless as ever, spoke coldly:
“The fight is over.”

And with that, he crushed Ivan’s wrist bones in his grasp.
“KRAAAAAAGH!!”
Ivan screamed and collapsed as both his arms were pulverized in a wave of unbearable pain.

“Me! I—Ivan, the strongest in the world—lost to a mere Japanese high schooler!”
As he writhed on the floor, shouting in fury, Kim Yu-seong kicked him in the jaw and spoke.
“I’m Korean.”

***
One of the legendary Seven Fist Saints!
CEO of the megacorporation Easter Egg Company! Three-time champion of the 1st, 2nd, and 3rd God of Fist tournament—Destruction God Ivan!

His humiliating defeat sent massive shockwaves through the underworld!
The fall of a living legend and the emergence of a new star worthy of replacing him!
And the fact that it was a mere 17-year-old high school student only fueled the buzz!

Those who watched the secret footage of the bloody brawl at Ueno Park—uploaded anonymously—racked their brains to come up with a suitable nickname for the one who took down a legend and became a new legend.
A body as solid as diamond!
Superhuman strength akin to Heracles from myth!

Fighting spirit like a night demon, yet mercy in sparing the enemy’s life!
Those who knew the fight had started purely by coincidence remembered that Ivan had mistaken Kim Yu-seong for Black Yasha—and thus gave him the nickname:
Diamond Yasha.

Even if that overwhelming combat power was a one-time miracle…
The martial world—unaware of that fact—was now focused on the insane Japanese high schooler who had taken down one of the underworld’s greatest figures, Destruction God Ivan, from the very moment of his debut!
However, Kim Yu-seong—the very subject of all these rumors—had no idea the world’s eyes were now upon him!

Because he was just an ordinary high schooler…
…who just happened to have a bit more muscle than most.