In the underground city, within a modest, dimly lit room, a young boy jolted awake, his eyes wide with confusion and disorientation. He frantically scanned the unfamiliar surroundings, trying to make sense of what had just occurred. Slowly, the fog in his mind began to lift, allowing the flood of memories from his past life to come rushing back.

He lifted a trembling hand before his face, inspecting it as though he were seeing it for the first time. "I'm alive again," he whispered, his voice soft, almost disbelieving, as if speaking the thought made it more real. Relief surged through him after a moment of silence. "Thank God, I'm human... and a boy, too." But then a lingering question gnawed at him. "How am I alive again?"

Suddenly, he remembered the hospital—the sterile room, the suffocating scent of antiseptic, and the faces of his parents, streaked with tears, as he slipped into the dark void. His last moments were spent battling cancer, confined to a hospital bed. During those long days, he had found solace in fantasy novels, where characters were often reincarnated into new worlds. In many of those stories, the protagonist would either occupy a new body or awaken in a different world, their past life memories slowly resurfacing.

He mulled over this, trying to make sense of his situation. 'If it's the first scenario,' he thought, *I wouldn't have any memories of this body's past.' But if it were the second, *my own memories should provide answers...' He focused, searching his mind for any hints, any clues, that might explain this second chance at life.

The first question surfaced in his mind: 'Who am I?' As soon as he thought it, a memory resurfaced, a name. 'My name is Rain.' 

"Rain," he murmured in shock, for in his past life, he was also Rain—Rain Jonas Malhotra. His mind raced, grasping for more. The second question followed swiftly: 'Who gave me my name?' Again, the memory emerged: 'I did. I gave myself the name Rain.' 

The reasons for this unusual act began to come back to him. In this new world, eerily similar to Earth, a nuclear war had ravaged the planet a thousand years ago. The war had broken out among the nations, and in the aftermath, the survivors took refuge in bunkers, grappling with the collapse of their countries. Outside, the land had turned inhospitable, frozen and irradiated, making survival in the open impossible. In just one month, human civilization was reduced to ashes.

Isolated in their bunkers, people were cut off from one another, forced to develop their own ways of life. Some bunkers, with more resources and better organization, managed to thrive, transforming their underground shelters into small towns with distinct, new cultures. Among them, three bunkers rose above the rest, becoming the most advanced.

Two centuries passed as the people of these underground cities adapted to their new reality. But as progress slowed, the inhabitants of the three great bunkers sought answers. They built robots to explore the desolate surface, desperate to rediscover the world they had lost. 

What those robots uncovered, however, was an astonishing, shocking truth: the surface world was teeming with life. But these were not the plants and animals of the past. They had transformed—mutated—into beings capable of manipulating the elements. Creatures wielding fire, water, ice, and thunder roamed freely, thriving in a world that, according to previous reports, was supposed to be uninhabitable due to extreme radiation levels. Yet the footage from the robots clearly showed otherwise.

The three underground cities were thrown into a frenzy. How could these creatures survive, let alone thrive, in such a hostile environment? The leaders were desperate for answers, and soon, a new plan emerged: capture these animals and study them to unlock their secrets. Combat robots were developed for this exact purpose, but capturing the creatures proved to be a challenge. After numerous failed attempts, the cities finally succeeded, each managing to bring back one specimen—Silver Blood Snake, Armor Dog, and Fire Cat, respectively.

What the scientists discovered was nothing short of groundbreaking. The creatures' genetic structure had undergone dramatic changes, allowing them to adapt to the new, irradiated environment. These mutations not only enabled survival but also granted them elemental powers. The implications were clear, and one burning question took root in everyone's mind: 'How could humans—once the rulers of the Earth, the top of the food chain—reclaim their dominance?'

The answer, as the scientists from the three cities soon concluded, lay in gene fusion. By combining human genes with those of the mutated animals, they believed it would be possible for humans to not only survive on the surface but to harness similar elemental powers. And so, without hesitation, research began. The entire population, driven by the desire to reclaim the world and fuelled by the allure of power, supported the project. For some, it wasn't just about survival—it was about rising even higher than before.

After numerous failed attempts, which resulted in death and madness for many test subjects, they finally succeeded. The first successful fusion of human and animal genes marked the dawn of a new era. As more people underwent the transformation, the results were mixed—many perished, while a few survived. Those who did survive emerged with newfound strength, elemental abilities, and, most notably, an increased lifespan.

Faced with both triumph and tragedy, the city paused its efforts. They needed to understand why some individuals were successful while others failed. In the meantime, the newly transformed warriors were sent back to the surface to capture more mutated animals for further research. Some missions succeeded, but many of these enhanced humans fell prey to the powerful beasts that roamed the surface, their abilities proving inadequate against the monstrous creatures. The surface, once again, became a graveyard for those who ventured too far.

Realizing the futility of sending more warriors to their deaths, the cities halted expeditions and refocused their efforts on studying the transformed humans. They sought to uncover the secret behind the success stories. Through extensive interviews and examinations of the surviving transformed humans, the scientists finally stumbled upon a critical discovery: the successful individuals had somehow unlocked what they referred to as "genetic locks." This breakthrough provided the key not only to survival but to the enhancement of the new human race.

Rain shook his head, pushing aside the flood of history. 'I can take the history class later,' he thought. He tried to control his thoughts, focusing on why he had chosen his own name. When he was 10, just before leaving the orphanage where he had lived his entire life, they had asked him if he wanted to change his name. The name 'Rain' had come to him in that moment, and without hesitation, he gave himself the name.

Now, the next pressing question surfaced: 'Where am I? What was I doing before my memories awakened?' As he pondered this, new memories emerged. He was in his room on the 6th floor underground, on the Educational and Research Floor of the city of Walter.

'What was I doing before?' The answer came swiftly: he had been in the process of opening his Spirit Gate, the key step to becoming a genetic warrior. Over the last 800 years, humanity had evolved, perfecting the cultivation system known as the 'Genetic Warrior Path.' While genetic medicine was still required to complete the transformation, the discovery of the Spirit Gate had revolutionized the process, increasing the success rate to 90% for those who could open it.

Rain realized he now needed to inform the school principal of his breakthrough before graduation. Once confirmed, the city would provide him with a genetic potion in exchange for signing a contract with Walter. He had little choice in the matter—he was an orphan raised by Spark Technology, the city's AI governing body. For children like him, opening the Spirit Gate before graduation, which typically occurred around age 16, meant they would receive a medium-quality, D-rank genetic potion from the city. With his Spirit Gate now open, Rain knew he could claim his genetic medicine tomorrow.

He glanced at the clock—11:47 PM. School started at 7:30 AM. *I should go to sleep,* Rain thought, his body finally succumbing to the weight of exhaustion. *If I don't, I'll never wake up in time.*

But the sleep that followed was anything but restful. Rain startled awake, gasping for breath, his heart pounding in his chest. He had just been trapped in a nightmare, locked in battle with a horrific stitched corpse monster. The details were still painfully vivid in his mind, as if he had truly fought the creature. He could still feel the force of each blow, the cold malice of the monster, and the suffocating terror it brought. He shuddered, trying to dispel the lingering fear. *How had it ended?* Had he defeated the monster, or had it overpowered him? The memory blurred, leaving him unsettled.

He turned over in bed, his eyes catching the dim glow of the clock: 4:04 AM. Despite his best efforts, sleep refused to return. Rain lay there, his mind restless, swirling with thoughts. *Golden fingers,* he mused. In every novel he had read, the protagonist was gifted with some sort of "golden finger"—a unique advantage that propelled them through their journey. Maybe he had one too.

"System," he called out softly, hoping for a response. Nothing.

'Maybe it's something within my mind,' he thought. He closed his eyes again, this time focusing on meditation, attempting to clear his thoughts. Slowly, the chaotic noise in his head quieted, and he began to sense the subtle energy flowing through his body. As his focus deepened, his awareness shifted to the 'Spiritual Gate' within his brain. It hovered there, in a state between existence and non-existence, elusive but tangible.

He tried to probe the gate further, curious about what lay inside. As his thoughts ventured into the Spiritual Gate, he found himself standing in a vast, black space. It felt endless, a void stretching infinitely in all directions. His consciousness lingered there, and though he could still sense his body outside, this black space felt unnervingly real. He began walking, moving forward in what felt like an endless journey. Hours seemed to pass, but the void stretched on without end.

Frustration gnawed at him. 'What did I learn about the Spiritual Gate in class?' He tried to recall the lessons, searching for any clue that might explain this strange space and how he could navigate it.