Marvel: My Sign-in System

In an unknown location and time, within a secret base, Leon stood in a small, damp room of less than fifteen square meters. He wore a thin white gown, leaning against the cold brick wall with his eyes closed. He had no expectations in his heart.

For a month, no one realized that this little boy had changed—his soul no longer belonged to this world. Leon was both unfortunate and lucky. He didn't know why he had suddenly traveled through time in his sleep and taken over the boy's body. Every few days, he endured human experiments that were almost unbearable.

Leon estimated that the boy had died a month ago, unable to withstand the torment, allowing him to take over. Over the past month, Leon came to understand the excruciating pain of these experiments. A mature mind could barely survive, let alone a child.

But he held on to the hope of escape.

He quietly suppressed his expectations, counting the passage of time. Finally, a metallic voice broke the silence:

[Ding!! Would you like to start signing in?]

Leon's breathing quickened. "Sign in," he whispered.

[Ding, sign-in reward: Glint-Glint Fruit(Pika Pika no Mi).]

As the voice faded, a fruit appeared in his hand. Feeling its rough texture, Leon's heart filled with joy. The Glint-Glint Fruit—one of the top Devil Fruits from One Piece.

As a Glint Man, his body could transform into light, moving at the speed of light and using the characteristics of light as a weapon. Though limited by the straight-line propagation of light, with the "Yata Mirror" technique, he could achieve freedom of movement. His only weaknesses were Haki, Seastone weapons, or the Dark-Dark Fruit's abilities.

In this world, without the Seastone factor, even the curse of being unable to swim no longer applied. Leon realized that, here, the Light Human had no limitations.

Suppressing his excitement, Leon glanced at the CCTV in the corner without drawing attention. He shifted slightly, positioning his body to create a blind spot that blocked both the camera and anyone outside the barred door who might look in.

He tilted his body, lowered his head, and raised his arms slightly as he took a bite of the Devil Fruit. The taste was indescribably sour and foul, but he forced himself to eat it all. He couldn't leave any evidence behind.

Afterward, Leon sat up straight and closed his eyes, focusing on the changes in his body. Slowly, a mysterious power began to take hold, and he knew that by the end of the night, he would be transformed.

The next morning, there was a loud bang.

"Hey, kid, your breakfast."

A deep voice came from outside the barred door. Leon, who had been leaning against the wall all night, opened his eyes and looked at the metal dinner plate that had been thrown to the ground. He glanced at the man who was distributing meals to the other test subjects in the nearby cells.

Leon got out of bed, bent down, and picked up the dinner plate. On it was a box of nutrient solution. For the past six months, this tasteless, specially prepared solution was all he had eaten. It was unpleasant, but undeniably nutritious. The experimenters didn't show mercy; they just wanted the test subjects healthy enough to survive the experiments.

He tore open the carton and drank it down. This was his main source of sustenance, gradually strengthening his body. Leon wasn't going to waste it.

After finishing, he placed the empty carton back on the dinner plate and set it on the ground for collection. Then he returned to his bed, closed his eyes, and began planning his next move.

The interval between experiments was five days. Since he had undergone one yesterday, that meant he had five days left, including today. By the sixth day, the changes in his body would become noticeable to the experimenters.

His fate would be even worse if he failed. So, Leon knew he had to make the most of these five days.

His sign-in system, though powerful, was unpredictable. He could sign in every day, but the rewards were often disappointing. Three days ago, he signed in with high hopes and got nothing. Only then did he get lucky enough to receive the Glint-Glint Fruit.

He planned to sign in again on the fifth day. Until then, he needed to train—intensively.

With this in mind, Leon got up and started doing push-ups. When the person collecting dishes came by later, they didn't seem surprised. Leon had been exercising during his free time for the past month. In the confined space, there wasn't much else to do besides exercise and stare into space.

The man left, and Leon continued his push-ups, already noticing changes in his body. Previously, his thirteen-year-old frame was weak, barely able to manage thirty push-ups in a row. Now, he could easily do forty without breaking a sweat. The Glint-Glint Fruit was subtly transforming him.

"Five days left…" Leon thought grimly.

He had the memories of the boy's past six months and had personally endured the same torture. If it weren't for the sign-in system, he might have met the same fate as the boy. But now, Leon was determined to survive and eventually take revenge on the inhumane people responsible.

With this resolve, he began a rigorous five-day training regimen.

Time passed quickly. Over the five days, Leon trained relentlessly. He kept his workout sessions within normal limits, but shortened the rest periods. Later, under the CCTV's blind spot, he secretly switched to one-finger push-ups.

However, he didn't dare to use the Glint-Glint Fruit directly. He wasn't sure if it would alert the experimenters, and he wasn't willing to take that risk.

The nutrient solution provided rich sustenance, and with the power of the Glint-Glint Fruit, Leon's physical strength grew daily. By age thirteen, his fitness already surpassed that of most adults.

The Devil Fruit's abilities became instinctive the moment he consumed it. Even without consciously using them, he could access some preliminary powers, including elementalization.

The time had come.

On the fifth night, Leon, who appeared to be asleep, suddenly opened his eyes. A faint golden light flashed within them. He sat up slowly, put on his shoes, and calmly walked to the barred gate.

Buzz!

A dazzling golden light radiated from his body as he transformed into a being of light. He moved effortlessly through the iron bars, stepping out of his cell.

As soon as he exited, a loud, urgent siren blared throughout the base. The entire corridor in front of him pulsed with red lights.

Beep! Beep! Beep!

The alarm also startled the other children undergoing experiments in nearby rooms. They woke up in a panic, rushing to their iron gates, straining to see what was happening.

What they saw was unbelievable.

The guards in the base reacted quickly. Within seconds, the sound of heavy footsteps echoed down the corridor. A dozen uniformed men burst through the iron door at the end of the hallway, armed and ready.

They immediately spotted Leon approaching and their expressions darkened.

"Hey kid, who told you to come out?" The leader of the group barked.

As he reached for Leon, the boy suddenly grabbed his wrist. The strong man's face twisted in anger. "You brat, are you looking for a beating?"

He tried to use his strength to overpower Leon, but to his shock, the boy's slender hand held firm, preventing him from moving. This kind of strength was impossible for a child of twelve or thirteen.

The strong man was filled with disbelief. Just as he was about to speak, Leon raised his head slightly, and his youthful voice echoed through the corridor, standing out amidst the blaring sirens.

"It starts with you."

Bang!

Leon's white shoe, glowing with a hint of gold, shot up and slammed into the man's stomach with tremendous force, far beyond what any adult could muster. The impact sent the man flying backward, blood spraying from his mouth, as he crashed into the iron door at the end of the passage, knocking over several others in the process.

The remaining guards, professionally trained, reacted immediately. They drew their guns, ready to respond. But they were no match for Leon, who had already transformed into the Light Human.

In a flash of golden light, Leon moved faster than their eyes could track. Sharp pain shot through their bodies, and before they knew it, their vision went black as they lost consciousness.

With a few swift strikes, all of the dozen men lay dead on the ground, their necks twisted.

Leon, who had just taken the lives of more than a dozen people, felt no remorse—only a sense of relief. But it wasn't enough. The unbearable torture and pain he had endured had filled him with a deep, burning rage.

He glanced at the children watching from behind the iron bars, their expressions now filled with shock and excitement, something different from their previous numbness.

No one spoke, but Leon saw hope in their eyes.

"I will return," he said softly, uttering the words with quiet determination.

With that, he turned and ran down the corridor, leaving the children behind, their eyes filled with expectant hope.

Boom! Boom! Boom!

Chaos erupted throughout the base, with roars and screams echoing one after another.

In the main control room above, a man in combat uniform hurried in. The room buzzed with noise and urgency.

"Hurry! The subject has breached the second floor. Team three, provide immediate support! Seal all passages and activate the defense system!"

"The first and second teams have lost contact, and the third team is still fighting!"

"More than half of them are dead or injured, and they're calling for help!"

"What's going on?"

The man, frustrated by the chaos around him, grabbed a man in a white coat who was trying to leave and angrily demanded answers.

"Sir, an experimental subject is escaping the base. Our forces are trying to stop him, but the casualties are heavy," the subordinate replied, visibly shaken and sweating.

"How could this happen?" the man shouted, shoving his subordinate aside as he approached the information desk. He looked up at a large screen made up of thirteen massive LCD monitors, and what he saw shocked him.

On the screen, a small boy in a white gown was fighting dozens of soldiers in the base's corridor. The scene was almost a one-sided massacre. The heavily armed soldiers fired their weapons, but none of the bullets could hit the boy. He seemed to possess a superpower, transforming into golden light and moving effortlessly through the chaos. Every punch and kick he delivered was devastating.

In less than half a minute, the soldiers were nearly wiped out. Blood and corpses littered the corridor, leaving only the boy standing among the carnage. As if sensing that he was being watched, the boy turned his back to the camera and looked up at the monitor. His cold, ruthless eyes filled the screen.

The previously chaotic room fell silent as everyone stared at those eyes, their hearts pounding. One message was clear in his gaze: I will kill you all!

The intensity of the boy's murderous intent was palpable, piercing through the screen. It was unbelievable that such overwhelming power and hatred could come from a child not even thirteen years old. He was almost indistinguishable from a monster.

Buzz!

The boy turned into golden light again and vanished from the screen. The man reacted with frustration, shouting, "Damn it!"

"Mobilize all available forces to capture that kid immediately," he ordered, his face showing a mix of anger and excitement. Despite the crisis, he saw it as an opportunity. The boy's newfound power meant their experiment had succeeded, and they had to capture him. This could lead to creating a super-powered army in the future.

"Yes, sir," one of the men replied, though his voice faltered as he added, "Sir, most of our soldiers are already dead."

"What? They're all dead?" The man, shocked, stared at his subordinate in disbelief.

"Yes, sir. The boy was too fast and acted like a perfect killing machine. Our people were killed almost instantly."

"How many armed forces do we have left?"

"Only one combat team. We don't have many forces here at the test base."

The man's expression darkened as he realized the full extent of the situation. "What about our equipment?"

"All destroyed. The boy's laser beam took out our defenses."

"Are we saying our base has fallen to a boy under thirteen years old?"

"Unfortunately, yes, sir."

"Damn it!" The man swore and then gave his orders: "Upload all the data on the boy immediately, destroy all other data and information in the base, and evacuate at once."

He was asked if the automatic explosive devices had been activated to destroy all experimental subjects. The man snapped back, "Idiot, if we blow up the boy, our efforts will be wasted. I'll report this to the Baron and ensure the boy is captured."

After cursing, he turned and left.

Following the man's orders, the remaining staff quickly evacuated the base after uploading the data, taking less than five minutes to do so.

Five minutes later, Leon walked into the information center. He was visibly exhausted, having used more than half of his physical strength. If he hadn't remembered from his past experiences that there were few guards, he might have chosen to escape rather than fight his way through.

Using his elementalization ability was powerful but drained his energy quickly.

The room was empty, and the surveillance cameras were dark. Leon approached the information desk, but he couldn't make sense of it. He knew the base was deserted and that everyone had fled.

After a moment of thought, he turned and headed towards the lower levels of the base to help the children.

It was midnight, and the children, startled by the chaos, had fallen asleep. They were clinging to the iron railings and listening to the noises around them.