Tokyo slept—or at least, it seemed to. From above, the city glittered like a sea of molten stars, the hum of neon and distant traffic washing over streets that would, in a few hours, become a battlefield. Kurogane Riku, sixteen years old, sat atop the crumbling roof of an abandoned skyscraper, knees pulled to his chest, and crimson eyes scanning the city. His white hair shimmered faintly under the moonlight, strands catching the faint glow of streetlamps far below.
He wasn't supposed to be here. Not really. A "transfer student" was supposed to blend, to disappear. Yet here he was, perched like a predator, observing the city with a calmness that belied the storm coming.
"Riku-kun…" a voice whispered, breaking the night. He turned slightly, catching the flicker of shadow in the alley below.
A girl. Short, almost fragile-looking, with long indigo hair and golden eyes that seemed too bright for the dark streets.
"You shouldn't be wandering alone," she said. Her tone was soft but carried an edge of steel.
"I like the view," Riku said lightly, brushing a stray strand of hair from his eyes. "And besides… I have a feeling tonight isn't going to be quiet."
Her brow furrowed. "You… you feel it too?"
Riku didn't answer, his gaze shifting to the east side of the city where the night air seemed to warp, twisting in unnatural patterns. A faint ripple—a shimmer that didn't belong—danced above the surface of a nearby intersection. The faintest vibration, like the pulse of something alive, sent a shiver down his spine.
"Here we go," he muttered.
Before he could react further, the air split with a sound like tearing metal. A Rift—unstable, bleeding black and violet light—opened above the street below. From it, shadows leaked like ink into water, forming grotesque, writhing creatures that slithered toward the city. They were aberrant, unnatural, limbs jagged and faces twisted in impossible angles. The smell of ozone and decay hit Riku before he could blink.
People screamed in the streets. Cars swerved and collided as the first wave of shadow-creatures began to consume everything in their path. But to Riku, the scene was almost… boring. He had seen worse.
"Stay back!" he called to the girl, though she barely flinched. Instead, she gripped a small dagger etched with glowing runes, stepping forward as if the shadows were nothing.
"Why aren't you afraid?" she asked, eyes narrowing.
"I don't have time to be scared," he said, his voice flat. "This is the part where you either run… or die."
The first creature lunged, a mass of jagged limbs and eyes that blinked where no eyes should exist. Riku's hand hovered near his pocket, fingers brushing the cold surface of an object hidden there. The Forbidden Core.
He had never touched it before tonight—never even known it existed. The Core, an artifact born from collapsed dimensions, hummed faintly, almost calling him. And then instinct took over.
His fingers closed around it. A shockwave of light and shadow erupted in his palm, a tide of energy that bent the very fabric of reality. The Core glowed, crimson at first, then split into threads of silver and black, wrapping around Riku like living armor.
The creature screamed as the threads of energy tore into its form. Riku barely moved, yet shadow and light danced around him, striking limbs, dissolving them into ash. The girl's eyes widened.
"You… you're…" she whispered.
"Alive," Riku finished for her. "For now."
The Core pulsed again, and with it, Riku felt something change inside him. Power. Absolute, overwhelming, and terrifying. It didn't just protect him; it demanded obedience, bending shadows, forming blades, even manifesting small shields of silver light.
The girl—still frozen in awe—stepped closer, her voice trembling. "Who… what are you?"
Riku shrugged. "Someone who shouldn't exist. But… lucky for you, I'm here."
The next wave of creatures emerged from the Rift, bigger this time, their limbs stretching impossibly, mouths opening in silent screams. Riku raised his hand. Threads of shadow shot out, slicing through the first wave in a single motion. Silver light coiled around the black tendrils, forming a storm that disintegrated the aberrants before they could reach the humans below.
The girl finally moved, launching herself into the fray, dagger singing through air, arcs of gold magic leaving trails that froze the smaller shadows mid-air before shattering them.
"You're fast," Riku muttered, noting the precision of her strikes. She moved like a dancer, yet each motion was lethal, measured, and practiced beyond her apparent age.
"I've been… trained," she replied simply, as if that explained everything.
Riku tilted his head, watching her. There was something familiar about the intensity in her eyes—a hunger, a determination. Something that would recognize power if it appeared in front of her.
"Name?" he asked.
"Shirayuki Hikari," she said. "And you are…?"
"Riku," he said. "Kurogane Riku." He allowed a faint smirk to play at his lips as another wave of aberrants advanced. "Looks like we'll be dancing for a while."
The Rift pulsed violently, and with a sound like tearing metal and stone, it expanded. More creatures poured out, some larger, with jagged spines and eyes that blinked independently. Riku's crimson eyes glowed faintly as he summoned the full extent of the Core. Shadows coiled around his arms and legs, extending into razor-like tendrils. Silver light formed into blades, shields, and spears, each responding to his instinctive commands.
Shirayuki gasped. "How… how are you controlling that?"
"I don't know," Riku admitted, though his voice was calm. "It just… listens."
The battle escalated. Riku's movements became poetry in chaos: shadows slicing, light shielding, threads wrapping around creatures, ripping, disintegrating. Shirayuki followed, her dagger now glowing brighter, her magic arcs precise, almost in tandem with Riku's shadow-light symphony.
As the last aberrant collapsed into ash, the Rift above began to contract. The remaining shadows shrieked and were pulled back, vanishing into the void. The city lay in ruin, but for now, humanity had survived.
Riku's Core retracted slowly, threads dissolving into his palm. He exhaled, feeling the hum of power settle like a heartbeat inside him.
Shirayuki stepped closer, her golden eyes studying him intently. "You… you're not normal," she said softly.
Riku smirked faintly. "I try my best."
She hesitated. "You'll need training. Someone with that… power…" Her gaze flicked to the disappearing Rift, "...will be hunted. And the Academy… they'll want to know you exist."
Riku's smirk didn't falter. "Then I guess I'll have to be faster than everyone else."
Before Shirayuki could respond, a black van appeared silently on the street, doors opening like the maw of a predator. Men and women in dark uniforms jumped out, weapons raised, but they didn't aim at Riku. Instead, a calm voice echoed from the van's interior.
"Kurogane Riku. You have been observed. Your abilities are… exceptional. We would like to offer you guidance."
Riku's crimson eyes narrowed. "Guidance? Or recruitment?"
A slight smile curved the lips of the figure stepping out: tall, slim, wearing a long black coat that shimmered faintly in the residual light of the Rift. Golden eyes gleamed from a hood, and a presence so commanding it made Riku's hair stand on end.
"Both," the figure said. "We are the Interdimensional Academy. You have a choice: run, or learn to control what you are—and perhaps, change the fate of this world."
Riku glanced at Shirayuki. She shrugged, almost imperceptibly, but her eyes betrayed understanding. "It's your call," she said.
Riku rolled his shoulders, feeling the weight of his blade and the hum of the Core. "Then let's see what they have to teach," he said. "But know this… I'm not here to follow anyone's rules."
The figure nodded, eyes glinting with something that might have been amusement—or warning. "We wouldn't have it any other way."
The van doors closed, shadows swallowing them both. And in that moment, the world outside the Rift seemed to pause, as if waiting to see what Kurogane Riku would become.
Inside the vehicle, Riku sat back, crimson eyes catching the faint reflections of the Rift dissolving behind him. He didn't know what awaited at the Academy—monsters, rivals, maybe other dimension-crossed warriors like Shirayuki—but one thing was certain:
He wasn't going to be ordinary.
He was going to be a storm.
And for the first time, the Forbidden Core pulsed as if in agreement.