The iron bars clanged shut with a final, echoing thud. The mysterious figure's voice slithered through the cage like venom.
"So… you built a gym, did you, Kairo? You wanted to make people stronger, smarter, more disciplined. How poetic… that the very thing you created will become the forge of your suffering."
Before their eyes, the ground trembled violently. The forest floor split open as roots twisted upward, forming grotesque imitations of weights, benches, racks, and bars — all crafted from black iron and bone, pulsating with a sinister, living aura.
Leonhart's face went pale.
"T-this… this looks like your gym, Kairo… but cursed."
The figure grinned, his teeth flashing unnaturally white in the shadows.
"Exactly. I will train you until every muscle fiber screams, until your bones grind against each other, until you beg for the mercy of weakness. But weakness is death, and death is too merciful for you two."
"You need power for the sake of power. You need to make sure that you suffer endlessly or just die as a slave to your desires."
He snapped his fingers, and the weights multiplied — towering stacks far heavier than anything Kairo had ever seen in the kingdom's gym.
"Here, there are no limits. The bars will not break. The plates will not fall. You will train endlessly. And every drop of sweat you shed, every tear you cry, will feed me. You will become strong, yes — but strength will be your curse."
"And also, you will have conditioning training. You two don't have enough strength and length in your bones. I will make sure every single bone will crack and break and heal over and over again. I am doing this to use you as weapons. And yeah, you can call it hell… even though that would be paradise compared to this daily life."
Kairo clenched his fists, his voice trembling but firm.
"You can break my body… but you won't break my will. If I survive this hell, I'll use that strength for peace, not for you."
The figure chuckled darkly.
"Peace? Ha! You will soon learn — every rep, every set, every muscle torn and rebuilt will carry my shadow. Strength is pain. Remember that, little prince. And you think you are building muscle? No. I will make sure your body doesn't heal at all. I will make you paralyzed so that you won't even move or scream. I love your screams, but I have a sensitive sense of sound, you know it."
"Uhhh, I can't wait to torture you. Especially you, Kairo. He is too weak, but you are too strong and can handle it. He might die — he is delicate. But you… you won't die even if I kill you. You just can't die. You are immortal."
And so it began — Kairo and Leonhart, forced into a demonic gym of suffering, where each lift brought agony… yet also growth.
The air rippled. Shadows wrapped around Kairo and Leonhart, swallowing them in a suffocating darkness. Their bones cracked, their limbs stretched, muscles expanded, voices deepened.
Leonhart fell to his knees, clutching his chest.
"Wh-what's happening to us!?"
Kairo gasped as his body surged with unfamiliar strength. His height shot upward until he matched the towering men of this world. His boyish face hardened into that of an eighteen-year-old. His childhood was ripped away in a single, brutal moment.
The mysterious figure smirked, arms folded.
"Children… I cannot harm. That is my one weakness. But adults… oh, adults I can break as I please. So I'll fix that little problem. From now on, you are eighteen years old. Strong enough to endure… and suffer. I wish I could attack you when you are kids because I love eating kids — their meat is soft unlike adults."
Kairo clenched his jaw, fury burning in his eyes.
"You stole ten years of my childhood…"
The figure chuckled darkly.
"Stole? No, no… I gave you adulthood early. But do not think of this as a blessing. For the next ten years, you will not age. You will not die. You will not escape. You will train, fight, and bleed. And when your suffering is complete, you will be released back into your world as if no time passed at all… with strength beyond kings, and scars deeper than hell."
"I will conquer this world. I will make you two generals. You will be able to kill entire armies. I don't want hundreds of armies. I just need two men who are raised in hell — who will be so loyal to me that no amount of torture can make them disloyal."
Leonhart looked at Kairo, his face pale but resolute.
"So… we'll be trapped here as eighteen-year-olds for ten years. That means…"
Kairo's eyes narrowed.
"That means when we're finally free, we'll return to our families still young… but inside, we'll have lived through a decade of torment."
The figure laughed, his voice shaking the forest.
"Exactly. Now then… my gym of agony awaits. Let's see how long before you beg me to end it."
The cursed weights pulsed with black aura. Kairo and Leonhart exchanged a glance — fear in their eyes, but also fierce determination.
Kairo muttered, almost to himself:
"Then let's survive this, Leonhart. If this is our fate… we'll turn his curse into our strength."
The demonic gym loomed around them, waiting.
Every rep would bring agony.
Every set would test their will.
But in the heart of hell, two boys had already begun to resist.
And the true battle — the one for their souls — had only just started.
Kairo staggered, staring at his hands in disbelief. They were no longer small, childlike fingers — they were thick, veined, and calloused, like those of a warrior who had fought a hundred battles. His shoulders were broad, his chest heavy with muscle, his legs powerful like tree trunks.
Leonhart stumbled forward, clutching his head.
"H-Haruto… look at us…"
The two locked eyes, and their hearts skipped a beat.
They were towering — nine feet tall.
Their silhouettes dwarfed the average man of this world (who stood around eight feet five inches). They had already surpassed it at the mere age of eighteen. Their muscles rippled with unnatural maturity, carved as though by years of brutal discipline. Yet they had not lifted a single cursed weight.
Kairo's voice trembled as he pressed his palm against his abdomen, feeling the steel-like ridges.
"…We… we look like soldiers who've endured ten years of war. But we haven't even started suffering yet."
Leonhart exhaled sharply, his expression grim.
"If this is what we look like before the training begins… what kind of monsters does he intend to turn us into?"
The mysterious figure spread his arms wide, grinning with maniacal pride.
"Beautiful, isn't it? You were mere children yesterday… and now you are giants among giants. Nine feet tall, bodies carved by discipline you never lived. I gave you the look of men forged in fire, but none of the fire itself. That… you will earn."
Kairo clenched his fists, his shadow stretching long and menacing against the cursed gym floor.
"Even if you turn me into a giant… my heart is still mine. I won't let you corrupt it."
The figure tilted his head, amused.
"We'll see. By the time I'm done, even that noble heart of yours will beg for war."
The cursed weights began to hum, glowing faintly with a black aura. Kairo and Leonhart exchanged a final look of determination, their massive frames casting a defiant presence.
Two boys no longer.
Two men, cursed into giants.
Their suffering was only about to begin.
The floor beneath them shifted, reshaping into long, endless treadmills forged of black steel. Runes burned along their surface, glowing like molten veins.
Kairo's feet suddenly lurched forward.
"W-what—?!"
He tried to stop, but his legs moved on their own, pumping with inhuman force. His body slammed into a sprint, muscles straining. The cursed treadmill roared to life, its speed dial flashing 60 km/h.
Leonhart shouted, his deepened voice echoing in panic.
"My body — it's not listening!"
Both of them were running like beasts, their nine-foot frames pounding the metal, each step shaking the air. Their lungs heaved, yet their pace never slowed — because it wasn't theirs to control.
The mysterious figure watched, his grin wide, eyes gleaming with cruel amusement.
"Do you feel it? Your muscles screaming? Your hearts tearing? This is not training you choose. This is discipline engraved into your very flesh. Your will is irrelevant."
Sweat poured from Kairo's body, dripping like rain. His mind screamed to stop, but his legs kept moving, faster, harder. The cursed treadmill bent his body to its will, carving agony into every fiber.
Leonhart's roar split the chamber.
"If this continues… our legs will break!"
The figure leaned forward, whispering like a devil in their ears:
"Good. Then they will heal. And when they heal, they will be stronger. You cannot resist this. You cannot rest. Until you have become weapons."
Kairo's teeth ground together. His chest burned. His vision blurred. Yet through the torment, his heart whispered back:
No matter how much you make my body run, my spirit will never run from who I am.
The tormentor's voice cut through the roar of the treadmills once more.
"Well, not only that — your legs will be broken and twisted in unnatural ways. Spears will be thrown at your upper body, but you will tank them and just keep running like you don't even care that your enemies are attacking you."
"Until then, you can enjoy while I think of other tortures or experiments that will make you stronger."
The cursed gym pulsed with dark energy, the weights and machines humming with malicious intent.
Kairo and Leonhart ran on, their bodies already screaming, their wills the only thing keeping them from breaking.
The true hell had only just begun.
And in the heart of that hell, two boys — now forced into the bodies of giants — refused to surrender.
Their suffering would be endless.
But so would their resolve