Dislcaimer : I own my oc's but not Percy Jackson or the series Garo Knight.

Chapter 1 Gai , The Sliver Fang Knight 

"Where am I?"

A young man stood amidst a surreal, otherworldly expanse, his lean, athletic frame the product of years spent swimming and fighting. His muscles, though wiry, bore the definition of someone hardened by countless trials. Standing at 5'10" (178 cm), he moved with the effortless grace of a warrior forged in battle, every motion a testament to his demigod heritage.

His sea-green eyes were piercing, a blend of intensity and curiosity, reflecting the vibrant energy of the mysterious realm surrounding him. His messy black hair framed a face that carried traces of exhaustion and resilience in equal measure. He was dressed casually, yet with an edge of readiness: a white jacket draped over a simple black t-shirt, jeans, and scuffed black sneakers.

This was Percy—formerly known as Percy Jackson, two-time savior of Olympus and estranged son of Poseidon.

The full story of how he'd reached this point would have to wait. Right now, Percy's focus was on his surroundings: a world seemingly stitched together from streams of powerful energy, hues of light blue interwoven with shades of purple and dark blue. The air shimmered, alive with an almost tangible magic.

In the distance, something caught his eye. Curiosity stirred within him, pulling him forward with a sense of purpose. He moved swiftly, the grace of his demigod nature guiding his steps as the landscape began to shift and morph.

As he walked further, the vibrant energy of the realm melted away, replaced by a blank white expanse. Endless sky stretched out above him, mirrored by a rippling, water-like ground beneath his feet that felt solid yet liquid. In the center of it all, a colossal, Jupiter-like sphere floated above a shimmering platform, its presence both majestic and ominous.

Percy muttered to himself, "All I remember is getting that strange card from that fortune teller... and then—poof—I'm here."

Reaching into his white jacket, he pulled out the card in question. It was exquisite, like nothing he'd ever seen before. Intricate golden patterns spiraled across its surface, intertwined with delicate, feather-like designs. At the card's center, a radiant starburst seemed to pulse faintly with a life of its own. Celestial symbols adorned its border, glowing softly with an unearthly light, their meaning just out of reach.

Percy's eyes lingered on the card for a moment longer before his gaze was drawn ahead. A figure stood in the distance, the only other presence in this strange realm.

The figure resolved into the form of a young woman as he approached. She bore an uncanny resemblance to Shizune from Naruto, but with subtle, otherworldly differences. She wore a pristine white kimono, her feet clad in simple sandals. Her eyes, pure and unblemished white, radiated calm, and her lips curved into a warm, welcoming smile.

"Greetings, Perseus," the woman said, her voice carrying an otherworldly melody. She looked upon him with an expression that was both knowing and serene, her smile unwavering.

Percy stopped a few feet away from her, his sea-green eyes narrowing slightly, his instincts flaring with caution. "Who are you? And where the hell am I?"

The woman's smile deepened, her tone gentle and inviting. "All your questions will be answered, Perseus. But first… let us talk."

"Talk about what? Who are you? What is this place?" Percy demanded, his sea-green eyes narrowing as he scrutinized the woman in white.

His instincts bristled. Was this some sick trick by the so-called "righteous" gods? A ploy to lower his guard before slapping him in chains for his supposed "crimes"? The thought set his teeth on edge.

The woman, however, seemed unperturbed by his suspicion. She smiled gently and introduced herself. "My name is Yumiko, and this is the Realm of In-Between." She gestured gracefully to the endless expanse around them, her calm demeanor almost unsettling in its serenity.

"The Realm of In-Between?" Percy echoed, his gaze shifting from her to the strange, ethereal world. The words tasted foreign on his tongue, but they carried a weight that made his pulse quicken. His eyes darted to the rippling ground beneath him, the colossal sphere above, and the endless white sky that seemed to stretch on forever.

Yumiko parted her lips to speak again, but before she could, the air around them grew heavy. A chilling, oppressive energy swept through the realm like a frigid wind.

Suddenly, a thick black mist seeped into the world, curling and twisting unnaturally as it advanced. The vibrant energy of the realm dimmed in its presence, and the ground beneath their feet seemed to ripple more violently, as though the world itself was recoiling.

The realm—if it could feel—seemed to gasp, an otherworldly sound that reverberated through the air, sending shivers down Percy's spine. His body tensed, instincts honed from countless battles screaming at him to be on guard.

Percy turned sharply, his gaze snapping toward the encroaching mist. "What the hell is that?" he growled, his hand unconsciously reaching for a weapon that was no longer by his side.

Yumiko's serene expression faltered, a flicker of concern crossing her face. "It shouldn't be here," she murmured, her voice quiet but heavy with meaning. She raised a hand, her fingers glowing faintly with white light as she attempted to assess the dark presence.

The black mist churned and coalesced, a malicious energy radiating from its core. Percy's instincts screamed danger, but instead of fear, he felt a surge of adrenaline. His sea-green eyes burned with defiance as he took a step forward, placing himself protectively between Yumiko and the encroaching threat.

"Yumiko," he said, his voice steady, though his muscles were coiled like a spring. "You're gonna explain what's going on—fast. But first, tell me: how do we deal with that?"

Yumiko hesitated for only a moment before nodding, her voice firm despite the mounting tension. "Stand your ground, Perseus. This is no ordinary mist. It is a fragment of something far greater… and far more dangerous."

Percy smirked, though there was no humor in it. "Dangerous? Story of my life."

The black mist surged forward, its tendrils reaching out as if testing the air. Percy clenched his fists, his instincts readying him for a fight he had no idea how to win.

Percy's hand tightened around the shimmering card, his heart racing as the Yami's growl reverberated in his bones. With a deep breath, he focused on the energy pulsing within the card, urging it to respond. A warmth surged through him, a light that flickered but began to grow in strength, like the first rays of dawn breaking through the darkness.

The card in his palm began to shift, its golden surface gleaming brighter as it twisted and expanded, forming into the hilt of a sword. Percy's breath hitched as the sword materialized—its blade a gleaming silver, its edges sharp and etched with runes that glowed faintly with an otherworldly power.

With no time to waste, Percy thrust the sword forward, and a ripple of light washed over him. The transformation was instant, as if the world itself recognized his resolve. His body was encased in gleaming armor, silver and black, with intricate patterns that resembled wolf fur running along the shoulders and chest. His new form felt powerful, like something ancient and primal had awakened within him.

The wolf-like design on his armor pulsed, and with it, Percy's senses seemed to sharpen. He could feel the weight of the Yami's presence, the darkness swirling around them, and yet he stood unshaken. The armor fit him perfectly, almost as if it had always been a part of him. He could hear the rhythm of his own heartbeat, steady and sure, matching the thumping growl of the Yami as it reared back, preparing for its next strike.

Yumiko's voice reached him again, though this time it was almost like a whisper through the storm. "The sword is called the Gai Fang, a weapon forged from the light of your spirit. Use it wisely."

Percy nodded sharply, feeling the weight of the sword in his hand. It was real. And it was powerful.

The Yami lunged again, its jagged claws tearing through the air. This time, Percy was ready. With a swift motion, he slashed the Gai Fang across the creature's path, the blade cutting through the air with a sharp, resonant sound. The Yami recoiled, hissing as dark energy leaked from its wound. But it wasn't enough to stop it—its glowing red eyes burned with hatred, and the shadows around it thickened.

Percy gritted his teeth. "You're not gonna like this," he muttered, taking a step forward, his feet firm on the ground.

He raised the sword high, the silver light of the Gai Fang reflecting off the black mist, and with a fierce yell, he swung it down toward the Yami, unleashing a blast of radiant energy from the blade's edge. The beam of light cut through the darkness like a scorching ray of sunlight, slashing the creature's chest and sending it reeling backward.

The Yami let out a screech of agony as the energy carved into its form, its body writhing in pain, but the dark force that made it whole seemed to heal the damage as quickly as it was inflicted. Percy's heart pounded as he stood his ground, his grip tight on the sword, but he knew he had to do more.

It wasn't just about cutting through the darkness. It was about banishing it.

Yumiko's words echoed in his mind: Remain resolute. Wield the light within you.

Percy closed his eyes, letting the quiet stillness of the Realm of In-Between seep into his bones. The fear, the anger, the bitterness that had accumulated inside him for years—he let it all go. The rage he'd carried ever since being cast out by his father, the betrayal, the loneliness—it didn't matter now. Here, in this moment, he was no longer Percy Jackson, the discarded son of Poseidon. He was something more.

When he opened his eyes, they glowed with an inner light, a fierce determination burning brighter than before.

The sword pulsed in his grip, and he raised it once more, the Gai Fang now a beacon of hope and strength in his hands. He charged toward the Yami, the light of his soul flowing through the blade, a reflection of the strength he'd always had within him.

As he struck again, the light burst from the blade in a wave, drowning out the shadows, searing through the Yami's body until it let out a final, anguished scream. The creature's form crumbled to dust, leaving only a faint trace of the black mist, which dissipated into the ether.

Percy stood panting, the Gai Fang still glowing faintly in his hand. The silence that followed was heavy but filled with an unspoken triumph.

Yumiko stepped forward, her serene expression unwavering. "You've done it, Perseus. The Yami is gone. But this is only the beginning."

Percy looked at her, the last vestiges of tension leaving his body as the armor around him began to fade. "I don't know about you, but I'm starting to get the feeling that my life's never gonna be 'normal' again."

Yumiko smiled faintly. "No. But you're stronger now, Perseus. You have the potential to become more than you ever imagined. This world, the Realm of In-Between, needs someone like you. And so do the others."

Percy's brow furrowed. "The others?"

"The battle against darkness has just begun. And you," she said, "are destined to be one of its greatest defenders."

"Okay, the Yami's gone… for now," Percy said, the Gai Fang dissipating, leaving the familiar weight of the card in his hand. He glanced at it, a faint shimmer still clinging to its surface.

"But I've got a lot of questions, and I'm guessing you've got some answers." He looked pointedly at Yumiko.

"Who are you, really? And don't give me that 'Realm of In-Between' stuff. What's your angle in all this?"Yumiko's serene smile didn't waver, but Percy noticed a flicker of something in her white eyes – something that wasn't quite amusement.

"My purpose here is to guide," she said, her voice soft but firm. "To offer assistance to those who are… chosen."

"Chosen for what?" Percy scoffed. "Another prophecy? Another 'great destiny'? I've had my fill of those, thanks." He crossed his arms, the familiar weight of skepticism settling back onto his shoulders. He'd been burned too many times by grand pronouncements and manipulative deities to readily accept anything at face value.

"Not a prophecy, Perseus," Yumiko replied, her voice retaining its gentle melody. "A necessity. The balance between worlds is fragile. The Yami's incursion is a sign… a symptom of a greater imbalance. You were brought here because you possess the potential to restore that balance."

Percy snorted. "Me? Restore balance? I'm just a guy who got framed, betrayed by everyone I knew, and kicked out of my own world. I'm no savior, and I sure as hell don't want to be."

The bitterness in his voice was palpable, a raw wound that hadn't yet healed.

Yumiko inclined her head slightly. "Your past experiences… they have shaped you, Perseus. They have forged you into the warrior you are today.

The pain you've endured, the betrayals you've suffered… these have not weakened you. They have made you stronger. They have prepared you for this."

Percy's jaw tightened. "Prepared me for what? Fighting shadows in some weird limbo realm? That's not exactly how I envisioned my afterlife – or whatever this is." He gestured around at the stark white expanse.

"This is not the afterlife, Perseus," Yumiko corrected him. "This is a place between worlds, a nexus of realities. And the Yami… they are not mere shadows. They are manifestations of negativity, of despair, of the darkness that lurks in the hearts of all beings. They thrive on chaos and feed on fear."

"So, I'm supposed to be some kind of cosmic janitor, cleaning up everyone's bad vibes?" Percy asked, his tone laced with sarcasm.

"You are meant to be a guardian," Yumiko said, her gaze unwavering. "A protector. The Yami are drawn to this world because of a growing darkness within it. You were summoned here to be its shield."

"And why me?" Percy pressed. "Why not someone else? Someone who hasn't been through the wringer and back?"Yumiko's expression softened. "Because you understand darkness, Perseus. You have faced it within yourself. You have known betrayal and despair. You know what it is to lose everything. And yet… you still possess the capacity for hope. That is what makes you worthy."

Percy was silent for a moment, considering her words. They resonated with a part of him he'd tried to bury deep – the part that still believed in doing the right thing, even when it hurt. But he was still wary."Okay, let's say I buy all that," he said finally. "What's in it for me? Why should I risk my neck fighting these… Yami… for a world that isn't even mine?"

Yumiko's smile returned, a hint of something enigmatic in its depths. "You will find your own answers to that question, Perseus. But know this: your journey here is not just about saving this world. It is also about saving yourself."

Percy's brow furrowed. "Saving myself? What's that supposed to mean?"

Before Yumiko could elaborate, a ripple distorted the air nearby. The white ground shimmered, and a new form began to materialize. It was another Yami, but this one was different. Larger. More menacing. And it radiated a palpable aura of malice. Yumiko's serene expression vanished, replaced by a look of grave concern.

"It seems our conversation will have to wait," she said, her voice tight. "This one… this one is stronger than the last."

Percy's hand instinctively went to the card in his pocket. He might not know why he was here, and he might not trust Yumiko completely, but one thing was certain: he wasn't going to back down from a fight. Not again. "Looks like I've got another mess to clean up," he muttered, a flicker of grim determination in his sea-green eyes. He might not be a savior, but he was a fighter. And right now, that was enough.

Percy couldn't let up now. If this thing could regenerate, he had to find a way to finish it for good.

Yumiko stepped forward, her serene expression now set with determination. "Perseus, you must strike its core. The Yami is a manifestation of pure darkness, but even darkness has a heart. Find it, and you will end this battle."

Percy exhaled, scanning the creature as it recoiled, its mist-like tendrils writhing angrily. His eyes sharpened—there, within the swirling shadows, a flicker of something solid, something beating like a heart.

"Gotcha," he muttered.

Summoning all his strength, Percy dashed forward, his newfound armor making his movements swift and precise. The Yami lunged as well, its claws slicing through the air, but Percy ducked under its strike, twisting mid-air like a seasoned warrior. He raised the Gai Fang high, its silver light blazing brighter than ever.

With a powerful thrust, he drove the blade deep into the Yami's core.

For a split second, time seemed to stand still. The creature's body stiffened, its red eyes widening in horror. Then, with a deafening, otherworldly wail, the Yami exploded in a burst of light and shadow, its dark essence evaporating into the void.

Percy landed smoothly, panting, his grip still firm on the Gai Fang. He looked around—the oppressive weight of darkness was gone, replaced by the shimmering calm of the Realm of In-Between.

Yumiko approached, a hint of admiration in her expression. "Well done, Silver Fang Knight."

Percy blinked, glancing down at himself, then at his sword. "Silver Fang Knight?" he repeated.

Yumiko smiled. "That is the title you have earned, Perseus. And this is only the beginning of your journey."

Percy took a deep breath, the realization settling in. He had no idea what was ahead, but if this battle was just the start… then he was in for one hell of a ride.

Gripping the Gai Fang tighter, he smirked. "Bring it on.