Actions

Work Header

The Black Cat and the Invincible Girl

Summary:

“It’s addictive, isn’t it?” Yooyeon murmured.
Addictive was too simple of a word to describe the sensation of being so close to the Invincible Diamond. It was like a cold black hole. It was like a warm hug. It was a pleading voice. It was freedom. It was despair. It was everything Nakyoung ever dreamed of. It was all her deepest insecurities, laid out in front of her. It was a promise. It was the end. It was the beginning.

Kim Nakyoung never wanted superpowers, until suddenly the light energy of the Cosmos rested at her fingertips. At the Modhaus Academy for Junior Heroes, all Nakyoung desires is to go on a date with her longtime crush, Kim Yooyeon. But the rise of an ancient cult threatens to interrupt her quest for young love. Fate apparently loves to play games with Kim Nakyoung, and she never wins.

Chapter 1: Prologue: Are You Alive?

Notes:

Chapter titles come from tripleS songs/lyrics. The fic will be a total of 22 chapters + a prologue and epilogue. I couldn't incorporate every member into the main fic but anyone missing will get a cameo at least!

(See the end of the chapter for more notes.)

Chapter Text

The Modhaus Academy for Junior Heroes was the most prestigious hero training academy in the entire country, and one of the most renowned throughout the world. When Nakyoung joined the academy, it wasn’t out of excitement for exploring her powers, or joining the world of heroes. Unlike many of her classmates, Nakyoung wasn’t born with powers. She was one of the very lucky few to develop an evolution as they matured.

She wouldn’t be at this academy if there was anywhere else to go.

When Nakyoung took the Hero Academy Entrance Exam, there were all sorts of recruiters for different academies at the testing center. They tended to focus more on the younger students, the ones who were barely teenagers, but wanted to show off the evolutions they’d been practicing since kindergarten. Nakyoung was approached by numerous scouts, but it was the Modhaus Academy flyer that caught her attention. The front was decorated with rich blues and a fancy black outline. The tagline for Modhaus Academy was Where everything starts and ends; the academy of the Invincible Diamond.

Flipping through the booklet, she was met with images of the sprawling campus, the oversized gyms and training rooms. Sprinkled throughout the brochure were cutouts of the Invincible Girl, photoshopped over the campus images like a virtual tour guide. The academy boasted the highest collective GPA and evolution mastery in the country due to their unique ranking system. Modhaus Academy produced the best of the best heroes, and they weren’t afraid to flaunt it.

To say Nakyoung wanted to be admitted was a stretch, but she didn’t hate the idea so much. 

Apparently, she scored the highest on the entrance exam in her entire batch, and higher than most applicants in the entire annual cycle. So… there was that.

Modhaus Academy, just like every other academy in the world, looked better on paper than it actually was. Not that they lied - the same gyms and hangars and training supplies were still available, but it was all strictly controlled. Ranks one and two were drilled endlessly to improve their evolutions, and rank threes and above didn’t bother interacting with the lower ranked students. Once a student reached rank three, they were eligible to become junior heroes. Trainees would be drafted onto a junior hero team and sent out to complete Encounters in order to build their field experience. But the junior hero teams were often cliquey, and the higher ranks not on a team were left outcast.

So Nakyoung kept her head down, didn’t make friends, stayed reserved within herself. And she trained. Day after day, she went down to the private gyms and ran herself ragged. The entitled junior heroes all relied on their evolutions, each trying to one-up the last. Nakyoung was going to be better than that. She’d be the strongest physical combatant at Modhaus, with or without her evolution.

Quickly rising through the ranks, Nakyoung reached rank three in just a year and a half. Rank three was a turning point for aspiring trainees. Once she was a rank three, barely a day passed before Nakyoung was drafted onto a new, budding team with the callsign AAA. When she first joined, the team consisted of herself and two other members, but a fourth member was added shortly after to compensate.

“This is us,” Nakyoung muttered, unable to meet the eyes of her new members. They were all gathered in their newly assigned dorm with - thankfully - four single rooms to be shared amongst them. The common space was small, but the couch wasn’t as moldy as Nakyoung’s last dorm, so she counted it as a win.

Her teammates were an odd bunch. The short one to her right couldn’t have been older than 15, and she was burning bright red at the sheer awkwardness in the air. The member who joined right after Nakyoung was sat on the only single armchair and had an equally bad baby face. She was staring down at her hands and fidgeting with her academy-issued uniform.

The final, original member cleared her throat and stood up. “Nice to meet you all, I’ve been told by the academy that I’m your new leader,” she greeted. “My name is Yoon Seoyeon, rank four. Maybe we can go around and introduce ourselves properly?”

“What’s your power?” the newest recruit asked, peeking up at Seoyeon before looking down as soon as she saw the leader's face.

This is my evolution.

All three of them collectively jumped and leaned away from Seoyeon. “What the hell was that?” Nakyoung hissed, covering her ears.

“Thought projection,” Seoyeon answered calmly. “I can also skim surface thoughts, but I promise, I’m not actively looking,” she said quickly, not wanting her teammates to get the wrong impression of her.

Suspiciously, Nakyoung narrowed her eyes and put up a wall in her mind. You better not be spying, Yoon Seoyeon.

With a sigh, Seoyeon turned to Nakyoung. “Well it’s hard not to when you’re thought projecting back to me. I can hear it when you’re talking to me.”

“Yeah, well- try not to,” Nakyoung coughed.

“I can go next,” the kid spoke up, practically dying from the tension between the two oldest members. “I’m Jeong Hyerin. Rank three. I can mimic other people’s evolutions.”

“Are there any limits? Like you can’t mimic different evolution types?” Seoyeon questioned, taking mental notes on her teammates’ capabilities.

Hyerin shrugged. “I can only do one at a time. Other than that, it’s just like I have the same evolution as whoever I’m mimicking. I mimicked someone with super strength once and I was crazy sore the next day.”

“I get that,” the newest member agreed. “I control electricity. Sometimes I zap myself and,” she mimed getting electrocuted.

“Remind me not to try to mimic your evolution,” Hyerin chuckled nervously.

“I’m Gong Yubin,” she said, letting out an awkward giggle and staring down at the carpet like it was the most interesting thing in the world. “I just transferred here. I’ve been training at different academies across Seoul, but I finally got accepted at Modhaus.”

Seoyeon seemed genuinely impressed. “You must be high ranked then.”

But Yubin shook her head. “No, we don’t have ranking systems at the other academies, it’s based on seniority and grades. So I’m only rank three.”

That seemed to deflate Seoyeon’s brief excitement. She turned to Nakyoung. “What about you, Miss Broody?”

“I’m not broody,” Nakyoung grumbled. She reluctantly held out her hand and unsheathed her claws. They came out of her nails, sharp and dangerous. “Claws, enhanced reflexes. I always land on my feet."

“So you’re a black cat,” Seoyeon observed.

She was exactly right, but Nakyoung didn’t want to say it out loud. “I have the powers of a black cat,” she specified.

“It’s okay, unnie, people tell me I look like a cat sometimes,” Hyerin offered to calm the environment.

“And I’m a baby tiger,” Yubin added.

Seoyeon didn’t want to play along. “Well, I’m Pochacco,” she said somewhat sarcastically to her teammates. Rubbing her forehead, Seoyeon couldn’t help an extremely painful moan of mortification. “How are we going to handle missions together?”


The answer was: not well.

You all need to work more cohesively! Stop fighting shadows on your own!

Nakyoung staunchly ignored the voice in her head and focused on spinning her daggers in her hand. She swiped through shadow monster after shadow monster, watching them howl and dissolve into mist. Tossing up a small diamond, Nakyoung captured the smoke inside the jewel and pocketed it.

These types of Encounters were reserved solely for new junior hero teams. Easy to contain. In a semi-populated area so that professional heroes could respond if the situation went south. Low risk rating. The shadow monsters were appearing only within the fenced off area of the parking lot, putting no one except AAA in harm’s way. It was sunny out, middle of the summer, and although the shadow monsters chilled the area around them, they couldn’t form into anything more dangerous.

Across the parking lot, Yubin electrified an entire maze of cars, trapping a group of shadow monsters inside. Seoyeon hung back, running around the perimeter to make sure none of the monsters escaped. Hyerin was using her classmate’s intangibility to phase through the shadows and strike them in their confusion.

It didn’t take long for the Master Shadow to form. The hulking figure was a combination of smaller shadows, coalescing into one massive form of pure dark energy. It towered over the cars and crushed them without care. Even with Yubin’s powerful electric current, the Master Shadow remained unbothered and stomped its way towards Seoyeon.

“I got it!” Nakyoung yelled, running towards the huge shadow.

Negative, wait for us to regroup. Nakyoung!

She predictably ignored her team leader. Nakyoung jumped on top of a non-electrified car and launched herself at the Master Shadow. She got on top of its shoulders and stabbed her blades into the neck of the Master Shadow, earning a roar of displeasure from the creature. It bucked her off and Nakyoung went flying, but she righted herself in the air and landed carefully on all fours.

Without a second to breathe, Nakyoung took off towards the Master Shadow again. She slashed at its legs, bringing it down on one knee. “I’ve got you,” Nakyoung muttered and went for the chest. She buried her blades deep inside, grinning at the wail that split the air.

Use your claws! They’re more effective!

But Nakyoung dismissed all the directions she was being given. She pulled her blades out and went for the neck, slicing deep. She was so focused on going for the head that she forgot she hadn’t dealt with its arms yet.

Two large, smokey hands wrapped around Nakyoung’s frame. She grunted as she was lifted off the Master Shadow. Slashing wildly with her knives, Nakyoung couldn’t cause significant enough damage to get the shadow to release her.

Use your evolution! kept echoing in her head, but Nakyoung was more concerned about the crushing weight on her chest making it difficult to breathe. She kicked and squirmed, her teammates’ screams fading into dull white noise. The shadows were so cold. The dark energy seeped into Nakyoung’s skin, chilling her blood and urging her to close her eyes and give up fighting.

With a loud roar, the Master Shadow pressed its hands together. There was a loud, echoing crack.

Everything went black.


The car ride was lively with the sound of generic radio pop music and off-pitch voices singing along. Nakyoung’s father was in the driver’s seat, purposefully singing poorly to annoy his wife. Nakyoung and her older sister were dueting in the back seat, holding imaginary mics up to the other’s face.

“Enough, I can’t take it anymore!” her mom exclaimed, a grin on her face despite the faked annoyance.

“You know you can’t resist it, honey,” her dad chuckled, reaching over to squeeze his wife’s hand.

“Ew, no PDA in front of us,” Nakyoung’s sister complained, putting a hand over Nakyoung’s eyes. “Not in front of our Naky.”

Their dad let out a playful huff. “Come on, Naky’s finally an adult, she can handle seeing her parents being affectionate.”

18 or not, Nakyoung was still the baby of the family. “Nope, I don’t wanna see it,” Nakyoung shut her eyes. “Being in love is so embarrassing,” she decided.

That made everyone in the car crack up. “Is your family really so embarrassing to be around?” Her mom made a cute expression, like she was on a variety show.

“Mom,” Nakyoung groaned, her face turning red. “I meant like in a relationship, it’s so embarrassing when everyone knows how much you like someone else.” Then, just for the hell of it, she tacked on, “But yeah, you’re all embarrassing,” earning a chorus of groans from her family.

“Ah, teenage pining, something I don’t miss,” her sister sighed wistfully, as if she were that much older than Nakyoung.

Nakyoung shoved her shoulder and scoffed. “Shut up,” she whined. “It’s whatever, I don’t have time for that right now. I’ve got more important things to do, and I’ll do them all on my own.”

“Black cat Naky,” her sister teased.

“Black cat,” Nakyoung repeated with a grin.

She opened her mouth to say something more when a bright light suddenly blinded her. “Watch out!” someone yelled. It came too fast for Nakyoung to understand what was happening. There was a loud bang, and she was jerked against her seatbelt. Everything spun and Nakyoung was upside down, blood rushing to her head. She couldn’t even scream before something hard and metallic slammed into the back of her head. 

Everything went black. 


When Nakyoung woke up in the infirmary of Modhaus Academy, all three of her teammates were in the room with her. Hyerin was the first to notice her wake up. “Unnie! You’re alive!” she cried, wrapping her arms around Nakyoung. With a grunt, the junior hero rubbed her eyes and patted Hyerin awkwardly on the back.

“What happened?”

“You were being an idiot and got yourself-” Seoyeon stopped herself and let out a shaky breath. Despite the frustration and anger on her face, she looked ragged. Sunken cheeks, puffy red eyes. “We thought you were dead. Never pull that shit again,” Seoyeon grunted, shoving Nakyoung’s shoulder.

“Ow,” Nakyoung complained, her eyebrows furrowed. “Did we at least complete the Encounter?”

Seoyeon rolled her eyes. “Of course you only care about that.” She gestured to Yubin, who was passed out on the only couch in the private room. “She had an explosion when she saw you. Practically vaporized every shadow in a half mile radius. She’s been sleeping like crazy since then.”

“Was it-”

“-it’s not evolution exhaustion. The nurses cleared her,” Seoyeon answered before Nakyoung could get the words out.

It took a moment for the air to settle enough for the oldest member to breathe again. “How long was I out, then?”

“It’s been two days,” Hyerin supplied. “You’ve been stable for a while, but the nurses said your body needed to naturally recover.”

Nakyoung nodded slowly and took in all the new information. As hard as it was for her to say, the words were eating at her since waking up and seeing all their weakened frames. “I’m sorry,” Nakyoung murmured.

Seoyeon perked up. “What was that?”

“I’m sorry.”

“I don’t think I quite got that.”

“Yoon Seoyeon, you can read minds, you heard me the first time,” Nakyoung grumbled.

With a soft chuckle, Seoyeon backed off. “Okay, I won’t push. I accept your apology. But you have to promise to start listening to orders. Not just for me, but for yourself, and the rest of the team.” Seoyeon put a hand on Hyerin’s shoulder, easing the youngest’s sore muscles. “We rely on you, whether you realize it or not. Please trust us too.”

She swallowed. It had been a long time since Nakyoung let anyone in. Since she trusted and shared some of the burden on her shoulders. But… she looked around the small room. Yubin, asleep on the couch, looking like she’d drained every bit of her evolution to protect Nakyoung. Hyerin, who kept inching closer to Nakyoung, her eyes flicking to Nakyoung’s neck and then darting away. And Seoyeon, who was so worn thin, trying desperately to hold all the strings together no matter how they slipped out of her hands.

“I’ll try,” Nakyoung croaked.

A breath slipped out of Seoyeon’s lips. “Thank you. Get some rest. We all need it.”


The Academy was quiet, all its staff and students safely tucked away in their dorms and offices. Nakyoung kneeled in front of the small memorial altar in one of the forgotten rooms in the student life section of the academy. Not many visited, judging by the dust lining the edges of the room, but Nakyoung didn’t care. It was a nice place to come to when things became too much. It was only Nakyoung, the silence, and the comfort of the three flickering candle flames she lit herself.

Nakyoung didn’t say anything. She’d spoken enough words to last a lifetime, and she didn’t want to repeat them. Just being in the warm presence of the flames was enough for her. She closed her eyes and breathed in the musty, dead scent of the room.

“It’s late to be out,” someone spoke from behind her.

Whipping around, Nakyoung came face to face with a ghost. She nearly panicked at the appearance of the girl with extremely pale skin and dark hair. She seemed so ethereal, wrapped in the dim lighting from the memorial altar. But upon closer inspection, Nakyoung realized this girl was real. The expression on her face was too complex to read, too interwoven to be an apparition. She was solid, even if she appeared to walk on air.

“There’s no rule saying I can’t be here,” Nakyoung shot back.

The girl approached slowly, the fire lighting her face better. Nakyoung’s memory tickled with recognition. How she’d missed it earlier was a mystery. 

The Invincible Girl. 

Her face was plastered all over Modhaus Academy. Kim Yooyeon was a legend to every student at the Academy, probably to every person across South Korea. Nakyoung was pretty sure she still had the pamphlet that convinced her to pick Modhaus Academy. It was Kim Yooyeon’s likeness in that booklet, the first Modhaus Academy student Nakyoung ever laid her eyes on, that brought her to this moment.

“I’m not kicking you out. Just concerned.” The Invincible Girl’s voice was silky smooth, at a low octave and carefully regulated to not allow the slightest hint of cadence to slip out.

“You don’t need to be. I’m fine,” Nakyoung instinctively defended.

Yooyeon gave her an inscrutable look. The girl kneeled down beside Nakyoung and faced the candles. She took one of the matches and scraped it against the box. When the sparks took, she lit a single candle and then shook the match to put the fire out.

An uncomfortable silence settled between them. Yooyeon shut her eyes and didn’t bother engaging in conversation with Nakyoung. Meanwhile, Nakyoung couldn’t help herself from continuously glancing over at Yooyeon to try and analyze her. Yooyeon was like a statue, and Nakyoung was never good at interpreting art.

Eventually, Nakyoung couldn’t take it anymore and she stood up, making for the door. “They’re still with you.” Nakyoung froze and turned around. Yooyeon hadn’t moved from her position, eyes still closed and mouth in a soft line.

“What?”

“They’re still with you,” Yooyeon repeated. “The way you carry yourself. They’re alive within you. They’d be proud of you.”

She stiffened, heart pounding at the poignant words. “You don’t know anything about me.” Her voice broke slightly.

“I don’t,” Yooyeon agreed. She didn’t try to appeal to Nakyoung or lead her astray with pretty words. She spoke bluntly, conviction in her words. “I just think that’s what you need to hear.”

Nakyoung stared. Long and hard. Yooyeon didn’t move or acknowledge her again, but her words kept echoing in Nakyoung’s head.

They’d be proud of you.

Her heart fluttered. Nakyoung gulped and swiftly made her exit, unexpectedly suffocating in the memorial room with Yooyeon. She didn’t know where the sudden warmth came from, but she couldn’t calm her heart down. With every step back towards her dorm, Nakyoung felt a strange, burning desire in her to return to the room, even for just one last glimpse of the strange, Invincible Girl she’d left behind.


“What do you think of heroes, Naky-ah? Don’t you think it would be fun to be one?”

“What powers would you kids want to have?”

“They’re called evolutions, Dad.”

“Powers, evolutions, you already sound like an academy kid. A Kim moving up in the world.”

“I think I’d want to have a siren voice. Like luring villains in before BAM taking them out. What about you, Naky?”

“Hmm… I don’t know. I’d be okay with any powers if it meant I can help people.”

“Ugh, how boring.”

“Hey!”

“Come on, don’t antagonize your sister. It’s really admirable to want to protect everyday people, Nakyoung. You know we’ll all support you no matter what you do. You’re really the best of us, we’re so proud of you, Naky-ah.”

Notes:

Hi! Thanks for checking out the first chapter of Black Cat Invincible Girl! I think superhero fics are incredibly common, but they'll always be a favorite of mine, so I wanted to take a crack at it. This fic incorporates a lot of original lore, but I tried to build it around tripleS terminology and traditional magic girl tropes. I'm also a huge TwoTenz shooter so ofc it had to be them.

Sorry in advance but we are NEVER getting biblically accurate AAA (I miss them). This fic is a terrible offender of not using biblically accurate tripleS dimensions (KRE about to be the worst offender...). Nakyoung is way broodier in the prologue than she is in the rest of the fic, I'm just contractually obligated to set up her tragic backstory before allowing her some happiness. Next chapter we time skip to the present and meet the rest of the characters, I hope you'll look forward to it!