[This is how it began—the brightest fall the world had ever seen.]
When Light first came down to the world, an angel named Valkyrie blessed the land.
Peace followed her. Warmth. Hope.
But it never lasts.
From the shadow rose a devil, Sakaris, greedy for the Cores—ancient sparks of power.
Light fought him. Shadow fought back. A war tore the world apart.
In the end, Valkyrie hid the Cores.
But before the war could end… it killed them both.
Both sides knew it wasn't over—just paused. Both waited to be reborn.
-
Five-year-old Eri lay on a huge bookshelf, a book twice her size open in front of her. Her snow-white hair spilled over the pages, and her blue eyes squinted at the letters.
"Va… Valk—" she whispered, struggling.
She tried her best to read at least a little. Maybe she was still too young to know how, but it's not like she had anything better to do.
At least, she wanted something to fill the endless time of her loneliness.
Even if it meant sneaking into the library and flipping through books whenever nobody was around.
But this time, it didn't last long.
A boy walked into the library and went straight toward the shelf she was lying on.
His quick steps gave away his rush.
"Eri?!"
Startled, she wobbled—then lost her balance.
Before she hit the floor, strong arms caught her. "Careful, little princess."
Eri's wide eyes stared up in disbelief at her brother, who was now holding her. "W-Why are you here?!"
Yeah, she was caught again, for what felt like the hundredth time this month.
Eric raised a brow, staring at this stubborn little girl in his arms. "Me? I should be asking you that!"
Eri bit her lip, guilty.
He couldn't help but let out a long sigh.
Eric only wanted one simple thing from her: 'don't leave your room.'
But every time, he ended up running all over the castle just to track her down and drag her back.
"If Father sees you out of your room again, we're both dead," he muttered, already moving toward the door. "Come on, let's get you back before—"
But Eri twisted out of his arms, scrambled onto his shoulder, and snatched the book. "No way! You're going to read this to me!"
His eyes widened as he saw the cover. "W-Where did you… find this?!"
Eri was sure if she told him again that she followed the lights, he'd just scold her over and over.
So she looked away, deciding to just spit it out quick. "On that table and yes, the lights showed me."
Eric's face darkened, a scowl forming.
The lights. Always the lights.
He had no idea how many more times Eri would chase after those stupid things.
She had never once obeyed a request without trouble. It drove him insane… and hurt, too.
"Those lights… again?!"
Before he could press further, heavy boots echoed in the hall.
"Prince Eric?! Are you in the library?"
Eric's eyes went wide with panic.
At this hour, a soldier had actually made it to the royal library?
If that soldier saw Eri here before Eric, they were doomed. Thanks to the angels, Eric had found her just a bit earlier.
He gritted under his breath, shoved Eri behind a shelf, and put a finger on her lips. "Activate it. Now!"
Eri clutched the book tight, fingers brushing her necklace. Then a faint glow flickered—and she vanished.
When the soldier entered, Eric was the picture of calm.
"I'm here. What is it?"
"King's looking for you, my prince."
"I'm busy. Tell him I'll come later."
The soldier bowed and left.
Eric let out a long, heavy breath and pressed a hand to his pounding chest.
That was way too close.
Finally he turned back. "You can come out n—"
Before he could finish, Eri reappeared with a giggle, leaping into his arms.
"Shhh!" he hissed, eyes wide. "What do you think you're doing?!"
"S-Sorry… brother." she mumbled, small hands clinging to him.
Eric's gaze softened at the sight of his innocent little sister in his arms. He sighed, ruffling her hair.
Anyway, he had no idea what to do with her.
What was the point of a hiding spell if she was gonna be this clumsy and noisy?
"I told you—once you activate the spell, don't move until I say. Got it?"
She nodded quickly.
He picked her up and, before leaving the library, glanced toward the end of the hall.
No table in sight, his frown deepened.
The lights kept luring Eri out of her room. They showed her things that weren't even real. And worse, they placed forbidden books—ones sealed and hidden—right in her path.
It was maddening.
Nothing could block those lights. The only way was for Eri herself to ignore them.
But she wouldn't even stay in her room, let alone abandon the only 'friends' she thought she had.
.
.
Deep in the farthest part of the castle.
Eric carried her down through endless steps.
The air grew heavy, the path narrow and suffocating.
Only the faint glow of a few light crystals guided the way.
It was the deepest dungeon a castle could ever have.
Finally, they reached a sealed wall of bricks.
Eric bit his finger, pressed blood to the stone—and the bricks started shifting aside, like a hidden door.
Inside was a tiny, dark room lit faintly by few light crystals here and there.
He set her down, sealing the door behind them. "How did you even unlock this again?"
"With my blood. The lights taught me," she said with a cheeky smile.
"Of course they did," Eric muttered, pinching the bridge of his nose.
He couldn't help thinking maybe he should just add another door to her room and lock it too.
How long would that even hold her before she figured it out again? A week?
"Eri… can't you just stay put? Why do you always sneak out?"
Eri gave her brother an innocent look.
The reason was obvious.
Anyone could see the almost depressed face of a lonely child.
Living alone in a cramped, sealed room, deep in the underground, surrounded by darkness—it was terrifying. Suffocating.
Especially when weeks went by without a single visit from her father or brother.
"It's just… lonely," she whispered.
Eric's expression softened, sat beside her on the bed, patting her head. "I'll come see you more, okay?"
"I wanna go out."
Eric shook his head at her same old request.
No matter how sad his sister got, going outside just wasn't an option.
"You can't." His tone was firm. "Remember our hide-and-seek game? If you leave your hiding spot, you lose."
At the mention of that stupid game, Eri flopped back on the bed and turned away from him, sulking. "I hate hide-and-seek."
"But Father loves it."
"Why this room? The path scares me every time."
Well, that was exactly the point.
They'd made sure the path was so scary and hard to reach that not only no castle servants would come near, but even Eri herself wouldn't dare sneak out—at least until she grew older.
But it didn't matter if she was scared. She was so stubborn that every time, she'd force herself to face it anyway.
"That's why you shouldn't leave," he sighed, his eyes fell on the book in her arms. "…And I need to take that from you."
"No way!" she snapped, hugging it tighter.
The book was forbidden. Eric had to take it and return it where it belonged, for angels' sake!
But how was he supposed to make Eri hand it over? At least, Eric knew he had to try.
The sooner, the better—before their father noticed.
"Eri. The lights aren't your friends. Since they showed you this, I have to take it."
"But I wanna know what's inside!"
Eric hesitated for a moment. "Fine. If I tell you some of it, will you hand it over?"
She thought a little, then reluctantly passed it to him.
"This book…" Eric said quietly, "It's about our world. The legacy of light and shadow. Passed down in our family for generations."
"You mean… Mommy wrote it… or Granny?"
"Maybe even earlier. But at some point… it stopped. Nobody added more. Hide-and-seek became more important."
Eri tilted her head. "Weird family. Then at least tell me the story."
Story? Eric could probably tell her a little, right? It's just a story. Nothing would really happen.
Then he just gave in, watching her eager eyes.
"Long ago, Light came to Earth. She helped people. Shadow came too, but he wanted the God-Cores. They fought. But the war never ended. One day, they'll both be reborn… to finish what they started."
Eri blinked, confused. "The… What-Cores?"
"God-Cores." Eric smiled. "The power of a god was shattered into eleven Cores. When someone is born, one of the Cores chooses them, forming a Nexus."
Eri touched her chin, nodding with a strangely thoughtful look for a five-year-old. "I see. So the Cores are power… even the Core of Milolo!"
Eric gave her a baffled look, rubbing the back of his head. "Uh… I don't think that has anything to do with it. Milolo's just a fruit. But… sure, okay."
"Then what Nexus do you have?" Eri asked.
He leaned closer, pulling down the collar of his shirt to show the left side of his neck, where a mark like a tattoo was etched. "A Space Nexus."
A broken line started from the center of his throat and spread left across his neck.
Each broken line represented a Nexus bond with its Core, each with its own pattern.
Five of them stretched toward the right side of the neck—the five positive Cores:
Light - Time - Life - Sky - Water
The other five, the negative ones, were mirrored on the left:
Shadow - Space - Death - Earth - Fire
The last one, Spirit, formed two perfect lines on both sides of the neck.
Eri grabbed one of the crystals nearby, trying to catch her reflection in it as she tilted her neck. "So… where's mine? I don't see it!"
He hesitated, watching her carefully before answering.
"You… you don't have a Nexus because… well, umm… because Nature itself loves you. The Master of Nature doesn't give the ones they loves the same powers everyone else gets."
For no reason at all, Eri's eyes lit up. She believed him instantly.
Pointing at the book, she grinned. "The Master of Nature loves me? So I'm special? Like the Lady Light in this story?"
And Eric's jaw just dropped. That was not the point of the story!
But before he could even panic about her logic—knocks rattled against the wall.
Eric stiffened and moved the bricks aside.
The King stepped in, face like stone. "She left the room again?"
Eri rushed forward. "Daddy! Did you read this book? Lady Light and Mister Shadow are reborn? Did you know that I'm special like lady light?"
Oh, perfect. She just exposed everything in five seconds flat. Eric was so dead.
The king's eyes snapped to the book on the bed, then glared at his 16-year-old son, Eric.
That alone was enough for Eric to realize how much trouble he'd caused.
He should've never told her anything.
"It's just a story," Eric cut in quickly.
Eri leaned her head a side a little. One of the lights — that only she could see — felt like it was whispering in her ear.
Then she slowly nodded and looked back at her father and brother. "But you said the next Light will be born in our family, So why are we hiding instead of fighting Shadow?"
"E-Eri…?" Eric froze. He cast a fearful glance at his father and quickly turned back to Eri, shaking her by the shoulders. "Please Eri! I never told you that. Why are you—"
"I only said if all the Lights hide, then Shadow wins." Eri replied to Eric, confused. "I just… I wanna be the Light, not the one hiding."
"Never say that again!" The King's voice thundered. "Give me the book! Now!"
Eri flinched innocently, hesitating, then slowly walked toward it.
"Why is Daddy always so angry?" she thought aloud.
Both of them watched her in worried silence.
Eric looked even more anxious. After all, he was the one who failed to take the book peacefully.
"She's too young," he whispered to their father. "Just… divert her mind."
She walked over to the bed and took a long look at the book.
Noticed glowing threads of light on the first page. Warm, gentle, calling her.
Quietly, she frowned, tore the page out and slipped it under her bed. Then she took on her innocent face again and handing over the rest.
The King's eyes softened.
He knelt, stroking her cheek. "Eri… I'm sorry I shouted. But promise me you'll keep playing hide-and-seek. For Daddy. Okay?"
Eri stepped back, turning her eyes away from him. "…For how long?"
The King paused.
For a long moment, silence filled the room as he searched for an answer—any answer.
What could he even say? The older she got, the harder this lie was to keep.
He needed to say something that would calm her down.
"Until…" He hesitated. Thinking about the answer he was about to give, he let out a heavy sigh. "Until your eighteenth birthday. Then the game ends."
The moment she heard when it would end, her whole mood lit up.
Her eyes went wide and she spun toward them. "Really? So if I wait, then I can get free?"
The King looked away, staring at the floor, unsure how to continue. "…Y-Yes. But only if you resist the lights and won't follow them again."
Eri twirled around in her tiny room, bursting with joy.
She was so happy that one day she'd finally be free and see the outside world that her heart raced from excitement.
Already in her head she started daydreaming about her eighteenth birthday.
"I won't follow them, Daddy! Promise!"
The King could only nod, unable to bear it any longer, he left. Eric silently followed after him.
She noticed, her smile faded a little. "Are you leaving already?"
Eric could say nothing, bowing his head in quiet frustration.
Eri, however, smiled up at him sweetly.
Reaching up with her tiny hands, she pressed them gently to his arms. "It's okay… I'll miss you too, and I want to be with you always, brother. But I'll wait until I'm eighteen. After that… I'll finally be free."
Eric managed only a faint smile… and a hug full of everything he couldn't bring himself to say.
'I hope this is just childish excitement and it fades quickly.' he thought as he left. 'Or maybe… if only time could freeze again…'
After Eric and the King left, she sat alone in her small room.
Pressed her hand to the sealed wall, "Just until eighteen… I'll ignore you…" she whispered "Then I'll be free… Daddy won't be mad… Brother won't be sad."
Her hand drifted to her chest.
Warm threads buzzed under her skin… but she shoved them down. Not now.
"Until eighteen… then it's over, right?"
-
[Thirteen years later]
A boy with black hair and blood-red eyes walked the castle's dark halls.
He looked cold. Calm. Like he didn't feel a thing.
He reached a massive door.
A fully armored knight, silent stepped aside.
Noah entered without a word, then the door slammed shut behind him.
The Emperor's chamber — grand, vast, and terrifying in its silence.
"Found her…?"