Nitrogen.
In South Korea, it's an expensive substance sold as the main ingredient in snack bags. In nature, it's the essential, foundational material plants need to synthesize protein.
Plants can't grow without nitrogen.
Without nitrogen, they can't do anything.
They just can't live at all.
And yet, ironically, plants can't use nitrogen in its natural form, even though it makes up 78% of the atmosphere. They can't go to the store, swipe a card, and suck in a nitrogen-packed snack bag.
The reason is simple.
'Plants can't get approved for a credit ca... no, it's because the triple bond structure of nitrogen molecules is too strong for plants to break. They can't split that bond, so the chemical reaction just doesn't happen.'
Kim Jangcheol searched his memory.
It was basic knowledge to him.
Thus, in nature, plants use nitrogen in the form of compounds like ammonia or nitrites, dissolved in the soil.
So what did humanity do once they realized this?
They developed a badass chemical process to revolutionize agriculture. Thanks to nitrogen fixation methods, factories started churning out ammonia-based nitrogen fertilizers like crazy. That's how the global population, which was just over a billion in the early 20th century, exploded into the billions within just a few decades.
'...Not exactly a method I can use here.'
No factory equipment.
No electricity.
Not even root nodule bacteria that naturally fix nitrogen in the soil — he had no way of getting those right now. Which meant he had to use another principle behind nitrogen fixation in nature.
And that was lightning.
'When lightning strikes, the high voltage oxidizes nitrogen into nitrites, which mix with rainwater and are absorbed into the soil.'
The amount of nitrogen fixed into Earth's soil this way each year? 9 million tons. That's how forests and fields stayed green even before humans ever threw fertilizer around. And now, the method he intended to use...
'Credos's signature skill — Bloody Lightning.'
Kim Jangcheol clenched his fist.
The final boss of Paladin of Blood, the Demon King Credos. He remembered all the times he died to that guy's Bloody Lightning while playing the game.
A crimson lightning bolt.
A terrifying shock.
The wind-up was short.
The casting motion, even shorter.
The activation, instantaneous — a monstrously overpowered skill!
"...Zephyros. Step back."
He gave the order.
So Zephyros wouldn't get caught in the lightning strike.
He took a step forward and steeled himself. He recalled how Credos would cast Bloody Lightning in the game. He mimicked it exactly. Raised his left hand. Tensed the nails on his right hand. Slashed the back of his left hand. Fast. Decisive. Without a moment's hesitation.
'Bloody!'
Zzzeujeok!
A sharp nail ripped across the back of his hand.
And with it came a wave of searing pain!
'...GAAAAAAAH!!'
Tears instantly welled up. Hesitation that hadn't existed before suddenly came flooding in. He hadn't expected it to hurt this much. No — thinking about it, of course it would. He'd just torn two centimeters of skin with a nail sharp as a spike. If this were real life? He'd be clutching his bleeding hand and sprinting to the nearest clinic.
'Credos, you bastard... did it hurt this much every time you used that skill?'
Not just anyone can be a Demon King.
Or maybe... he enjoyed it?
Was that guy one of those kinds of freaks?
A thousand thoughts raced through his head. To think he had to go through this kind of pain just to cast the skill once. And to fix enough nitrogen, he'd need to do this hundreds of times. The idea of having to keep doing this made his vision blur. He was honestly tempted to just look for a different method.
But still—
'Even so, it's better than dying!'
Better than invading the human realm and getting killed by Aged Kimchi.
Better than hesitating and getting chopped up by the Four Heavenly Kings.
A little sting in the hand didn't seem so bad in comparison. If he could succeed at farming, then maybe — just maybe — it'd all be worth it.
Kim Jangcheol clenched his teeth.
...Zzzeujeojeok!
He slashed his hand again.
Did he cut a blood vessel?
Dark crimson blood spurted out.
He flung it without hesitation.
'Lightning!'
Blood — the cursed blood of the Demon King — splattered like a fountain, following the arc of his slashed hand. It dyed the air red.
And at last—
Tok tok tok.
It splashed to the ground with a wet plop.
And that was it.
Nothing happened.
The crimson bolt of lightning? Never came.
The blood he'd flung so dramatically just left a few pitiful drops on the barren front yard of the Demon King's castle.
"...GAAAH—hngh—ah...ssibaaaaa…"
It wasn't worth it.
It just hurt like hell.
Tears pricked at the corners of his eyes.
But thanks to that pain, Kim Jangcheol realized—
'…It's a failure?'
It certainly seemed so.
They'd said that Credos's blood was steeped in the destructive instinct unique to the demon race. That merely spilling it would cause a lightning strike of destruction.
But now?
Nothing happened.
Even though he mimicked the casting exactly as Credos had in the game, nothing had occurred.
'Why?'
There must've been a reason. But he didn't have time to think about it.
Because suddenly, a voice spoke from behind him.
"Demon King Credos. Are you... feeling unwell, perhaps?"
"...!"
It wasn't Zephyros's voice.
It had the rasp of scraping rusted steel.
The moment he heard it, chills crawled down his spine.
Without thinking, he whipped his head around.
And there stood one of the Four Heavenly Kings — Asurat.
Wielding a jagged sword formed from dark red veins and sinew, openly held forward. He was staring at Kim Jangcheol — and at the blood he'd just wasted on the ground — going back and forth between the two with an ominous gaze.
"......"
What was the right thing to say in a moment like this?
Words failed him. And with the other Three Heavenly Kings — Sirgi, Hartok, and Baal — standing beside Asurat, his tongue felt all the more frozen.
"I…"
Still, he had to say something. If he stammered like an idiot, they'd see it as weakness. He'd die. That was unacceptable. Unthinkable.
But whatever response he was trying to muster got cut off by Asurat's chilling grin.
"Demon King. You do know our demon race's rule, don't you?"
"What?"
"The strong is the Demon King."
"..."
"That's why I'm curious."
"..."
Blatant.
Too blatant.
Asurat's gaze. His posture. Every small gesture oozed killing intent. No — that wasn't just malice.
Those eyes—
They were the eyes of a predator sizing up its prey.
Thanks to that, he was able to realize something.
That bastard had chosen today.
He had calculated every angle in advance.
'Shit.'
He never imagined that one of the Four Heavenly Kings would bare his fangs this openly, this soon. So what now? What should he do? He needed to think, but everything was happening too fast. Asurat was already stepping forward.
"......"
It was just a single step, but the suffocating pressure came crashing down like a wave. Was this what it felt like to stand face-to-face with an overwhelming predator? Unlike when he'd watched from the balcony earlier, this was fear, real and physical, pressing down on him.
His shoulders trembled. His teeth clattered with an audible sound. The corners of his eyes, the muscles in his cheeks, twitched and spasmed uncontrollably. He kept thinking, You can't let it show. If you let it show, it's over. But his body wouldn't stop trembling.
And thanks to that (somehow?)—
Asurat, tensed slightly as he took in Kim Jangcheol's reaction.
'…As expected of the Demon King, Credos.'
That twisted expression. The shivering shoulders, the twitching eyes — the fearsome sight of someone gathering such immense magical power already!
'He seems weaker than before, but… even so, the pressure he exerts can't be ignored. Still...'
Crack!
Asurat bared his fangs in a wicked grin.
"Can you defeat all four of us in your current state?"
That was it. He wasn't alone. If the Four Heavenly Kings attacked together? Credos, whose former might had clearly faded, wouldn't survive the onslaught. He'd be torn apart and meet his end.
Asurat looked back, full of confidence, at his fellow Heavenly Kings who would share in today's bloodbath. And what he saw was—
Those same comrades who had stood shoulder to shoulder with him just moments ago had, at some point, quietly retreated… about 50 meters back!
"...Huh?"
What?
What the hell?
Why are you over there?
Weren't we doing this together?
"...."
Stunned, Asurat questioned them with his eyes. The other Heavenly Kings, now standing far away, shook their heads rapidly. The message was clear — This doesn't feel right. We'll jump in later if it looks doable.
'...You damn cowards!'
Swears practically spilled from Asurat's eyes.
But the die had already been cast.
There was no backing out now.
"Demon King… Credooos!"
Shraaak!
The blood vessels and sinew coiled around Asurat's serrated blade lashed out, connecting to his hand and forearm. He pointed the jagged sword straight at Kim Jangcheol.
"Today! I, Asurat of the Blood Flame! Declare the Rule of Usurpation in pursuit of the Demon King's throne!"
It was a proclamation.
And the sky reacted.
A section of the crimson sky roared in response. Asurat's declaration of the Rule of Usurpation — the heavens above this forsaken land answered the call.
A hole opened in the storming black clouds.
A massive eye gazed down on the forsaken land. It fixated on two figures — the one who had declared the challenge, Asurat, and the one who had received it, Kim Jangcheol.
The bloodshot gaze transmitted the moment to every demon living in this desolate land, live and unfiltered.
Then, Asurat stomped the ground.
Fwoosh!
'This victory… is mine!'
A fierce grin curled on Asurat's lips.
The Demon King was weakened.
Now was the only chance.
If he seized this moment, he would become Demon King. He would claim the throne. Lead the army into the human world. His name would be carved into the demon race's history in eternal glory!
Asurat surged forward, his jagged blade glinting with violent resolve.
"........I—"
Kim Jangcheol's eyes flew wide open. A chill ran down his spine. He had to dodge. Had to do something. But his mind went completely blank.
'Am I… gonna die?'
Probably. After all, deep down, he was still just a human, and that guy was a demon — one of the Four Heavenly Kings, no less. This was only natural.
…He was about to fall into despair when it happened.
Tap!
Asurat's second step thundered against the ground as he charged forward.
And in that instant, Kim Jangcheol saw it.
'Huh?'
That second step Asurat took as he kicked off the ground—
The angle of his foot…
'...Outward?'
He'd seen this before.
In a flash, it came back to him.
The countless battles with Asurat in the game. The times he'd been cut down over and over — until he was forced to learn, forced to memorize every one of Asurat's movements.
'That's from the mix-up opener pattern… the thrust.'
His memory summoned his instincts.
His instincts triggered his reflexes.
His reflexes drove his body.
Whish!
Without thinking, Kim Jangcheol stepped his right foot half a pace back.
Twisted his waist.
Tilted his shoulders.
And then—
Whoosh!
Asurat's thrust, like a flash of thunder, grazed just past his chest. No — it simply cuts through empty air.
"What?!"
Asurat's eyes widened in disbelief.
Their gazes crossed for a split second.
The guy was stunned.
And in that stunned look, Kim Jangcheol realized—
'Every one of his movements... is exactly like the game.'
That was the moment it happened.
Ding!
Asurat's figure flashed by, staring at him in shocked disbelief — and suddenly, an unprecedented message appeared before his eyes.
[Kim Jangcheol, you have uncovered a basic rule of this world through direct experience. In addition, you have successfully used heightened focus to evade a lethal attack in the most refined manner.]
[As a reward, a portion of the gameplay system used by playable characters is now unlocked for your use.]
[Targeting Function, UNLOCK!]
"...!"
The moment he saw it, he understood.
What it meant.
What it implied.
He looked up.
Asurat, now aware that his first strike had missed, was already preparing the next blow. But above him, something new had appeared — a mark. A red square of targeting, fixed to him like a brand.
Its meaning was clear…
'...Bloody!'
Pzzzz!
He slashed his hand again.
The pain surged anew.
Crimson blood shot out.
He clenched his teeth hard.
He whipped his torn hand.
Blood sprayed, carving through the space.
And the moment Asurat charged in through that blood-soaked space — now marked by targeting—
CRACK!
"GYAAAHHH—!"
The targeting-exclusive skill — Bloody Lightning — descended in a violent flash, engulfing Asurat in its wrath.