March, the beginning of spring.
The hazy sky stretched in gray and black, emitting a heavy sense of oppression. It was as if someone had splattered ink onto drawing paper, letting it soak into the sky and smudge the clouds.
The clouds folded over each other, merging together. After that, streaks of lightning could be seen shooting out, accompanied by thunderous rumbling.
The classroom window was open, letting the spring breeze drift in freely, gently caressing the youth's face. A quietly handsome boy sat at the back of the classroom. The only sound that could be heard was the chalk in Teacher Nathan's hand as he wrote formula after formula on the board in a relentless manner, a smile on his face.
He seemed quite content in his heart.
The youth at the back sighed, gazing outside with his deep, dark eyes while enjoying the weather."Ah… today's weather is too good to be true…"
"What could possibly go wrong today?"
As he was thinking sudden voice rang out.
"I am here to make an announcement. You may call me Dest — a name I got from the word destruction."
Don't you think it's good?
He paused briefly.
"Never mind. Let's get to the main point."
"According to the Myriad Universe Association, no upper world is permitted to use brute force against lower beings — beings you call humans."
The one speaking was a two-horned, red-scaled demon nearly three meters tall. His figure was projected onto every possible screen around the world.
People all around the world were in shock. Some watched from their phones, others from their TVs — but all of them were in complete awe.
"So, bound by the rules, we can't use brute force to annihilate all of you and possess your world."
Somehow, his voice echoed across the entire world. Every human heard it as clearly as if he were speaking right beside them — loud and domineering.
"What? Annihilate us? Possess our world? I've never heard such bullshit," a fat kid in uniform said angrily.
"Maybe he's telling the truth. Have you ever seen something like him? It's a demon — literally from fiction or movies. Look at his red-scaled skin. Maybe we should listen until the end," a black-haired youth at the back said within the group.
"As he suggested, Finn's right. We should listen right until the end," a blonde-haired, big-eyed girl sitting right beside Finn said, nodding in agreement.
After that, their small group's conversation ended, and the demon continued his speech.
"However, we can force you to make a deal with us," he said, grinning wickedly and revealing razor-sharp teeth.
"No matter how much you try to resist, all the damn weapons you possess are meaningless against us demons. The reason the Myriad Universe Association exists is equality — equality among the myriad planets. So, in order to close the gap between us, we will change your world's ecological system to be as fierce as the Demonic World."
"As for changing the ecological system, demon beasts will appear. These beasts will vary in rank and power, and by defeating them, one will grow stronger — similar to games in your world. Of course, in every society, whether demon or human, there will always be those who stand above the rest… at least, I hope so."
"And lastly, we will grant you fifty years! After fifty years, we will attack without any warning and claim your world as our own."
He laughed loudly and disappeared from the air where he had been standing.
After the demon disappeared, the world fell into huge turmoil. Everyone debated whether they should believe it or not. In response, the presidents of every country made announcements — and all of them shared the same conclusion.
It turned out that what the demon said was completely true. If humanity failed to grow strong enough to protect the world from the approaching danger within fifty years, all life would cease to exist.
Some panicked. Some strong-willed individuals already understood the message — become stronger.
Finn and his group understood as well. However, they were in a bad mood; after all, they were just teenagers.
"Hanna, Yeger, are you guys okay?" he asked.
Hanna looked seconds away from crying. Fear was written all over her face.
But Yeger, for some reason, seemed to be in a good mood.
"Guess I finally found the perfect motivation to lose weight," he joked, laughing despite the situation.
Both Finn and Hanna stared at him with dumbfounded expressions.
"What? We just need to look at the bright side, right?"
Technically, he wasn't wrong — but neither of them was in the mood to see it that way.
Humanity had lived in relative peace for decades — ever since the end of World War II. But perhaps those peaceful days had ended here.
Panic spread quickly. Some people froze in terror, others forced themselves into cold stoicism, while a few even felt excitement — as if this catastrophe were a chance to escape the suffocating cycle of work, debt, and meaningless routine.
An hour after the demon disappeared, strange creatures began appearing all over the world.
Beasts that did not belong to Earth emerged without warning, each with a grotesque form — some were twisted hybrids of dogs and horses, darker and far more sinister; others were snakes with legs that walked upright; some were massive lizards, larger than crocodiles themselves.
Yet despite their different shapes, they all shared one thing in common: their skin and scales were tinted red — some crimson, others nearly black.
From that moment on, humanity reached a grim conclusion. Every beast from the Demon World bore that color.
"Finn… what should we do?"
Hanna asked in a trembling voice, fear clearly written across her face as she imagined what might come next.
Yeger also glanced at Finn from the side, silently waiting for an answer.
Finn took a slow breath before speaking.
"First, everything the demon said is true. That much is certain," he said calmly. "Right now, the entire world is probably in chaos — panic, riots, military mobilization."
He paused briefly, then continued.
"We can't stay passive, but acting recklessly is just as dangerous. The first thing we need to do is go home and wait for official announcements — from the government or the authorities."
What they didn't know was that the outside world had already become dangerous. Flies as large as human heads were flying all over the city of Delon. Long, sharp, needle-like stingers protruded from their bodies, dripping a toxic substance — making it clear that if one were struck, escaping alive would be impossible.
His eyes darkened slightly.
"As for the second part… from what we've seen, there's only one way to become stronger."
Finn looked at the distant streets, filled with flying flies.
"By killing them. Just like what we do in a game!"
"It's always a pleasure to hear that from a fellow gamer like me," Yeger laughed.
Finn and Yeger had both been good at gaming since a young age, but there was a difference between them. Finn always maintained a balance between gaming and school, while Yeger did not — his grades fell every semester, and he wasn't even this overweight originally. Despite all of that, they were always good friends.
Hanna had originally wanted to improve her grades by sitting beside Finn. She even tried to make use of her charm and beauty to put Finn under her influence, but it turned out that Finn was a lunatic who prioritized logic over feelings.
Despite being the same age, Finn was far more mature and controlled, no matter the situation. That was why both of them had always listened to Finn's leadership.
"The only difference is that in games, we always have a chance to play again after we die. But here, everything is real — and those bastards outside can do whatever they want with their stingers."
The students in the classroom were divided into groups by Teacher Nathan.
Somehow, Teacher Nathan remained very calm, thinking about everyone's safety.
"Kids, listen up!" he shouted. "Grab anything that can be used as a weapon or something that can protect you. You already know that staying here will only delay certain death."
"I'm expecting that the entire world is in chaos right now, so no one is coming to save you. You can only depend on yourself or your group."
"Lastly, we will get out of the school and find shelter, as the government has instructed."
Teacher Nathan led the students out of the classroom, Finn's group among them.
Then—
A sharp buzzing sound sliced through the air.
A fly, as large as a human head, burst into view. Its stinger gleamed like polished steel, long and needle-thin, radiating lethal intent. Fear drilled straight into the students' hearts.
One of the classroom windows was still open.
The creature slipped through effortlessly.
Screams erupted.
Hanna froze in place, her body trembling uncontrollably, tears welling in her eyes as her legs nearly gave out. Yeger stared at the creature with a strange mix of shock and fascination — but his feet refused to move.
Even Teacher Nathan's expression changed.
His brows knitted tightly as he stepped forward without hesitation, spreading his arms wide to shield the students behind him.
"Get back!" he shouted.
The fly suddenly accelerated.
Its speed was terrifying.
In an instant, the shining stinger was aimed straight at Teacher Nathan's face.
He didn't run.
He stood there, prepared to take the hit.
What he didn't realize was that one student was no longer behind him.
Just as the stinger was about to pierce through—
"Die, you bastard!"
A chair smashed down from the side.
PYAAD!
The massive fly was slammed violently into the floor. Its body burst apart on impact, purple, blood-like fluid splattering across the tiles in a sickening spray.
The buzzing stopped.
Despite its size, the creature's body was fragile — no stronger than an ordinary fly.
It twitched once.
Then went completely still.
Silence filled the hallway.
Teacher Nathan turned slowly, eyes wide.
Finn stood there, breathing heavily, the broken classroom chair still clutched in his hands. His heart was pounding violently, his arms were shaking.
His stomach churned.
The smell of the creature's strange blood filled his nose.
Then—
A cold, mechanical voice echoed inside his head.
You have slain a Mutated Fly.
You have gained access to the Demon's Cradle.