The System’s Debt

Kiaro barely slept that night.

He lay on the thin mattress of his rundown apartment, staring at the cracked ceiling above. The system’s interface hovered faintly in the corner of his vision, never disappearing, always watching. Renn had left him at the door with a quiet nod and a whispered “Tomorrow.” No demands. No further questions. Just a silent agreement.

But something felt wrong.

Kiaro sat up and pulled up his status window.

— Status —

Name: Kiaro

Rank: F (Hidden)

Level: 3

Strength: 7

Agility: 8

Endurance: 6

Mana: 3

Energy: 34%

He frowned.

Energy?

That hadn't been there before. He scrolled through the interface, searching for an explanation. Finally, a new message appeared—one he must have missed in the chaos of the fight.

[System Notice: Stat growth and skill activation consume Energy. Current Energy reserves: 34%. When Energy falls below 10%, physical performance will decline. Below 5%, system functions may shut down completely.]

Kiaro’s stomach tightened.

So there is a limit.

He had assumed the system was infinite. Unlimited growth with no cost. But this… this was a leash. A hidden chain wrapped around his newfound freedom.

[Energy Recovery: 2% per hour of rest. Alternatively, absorb monster cores to instantly restore Energy and increase maximum capacity.]

Monster cores.

Of course.

He had heard stories about them—crystallized mana taken from the heart of a slain monster. Higher-rank cores were worth small fortunes. Lower-rank cores were still valuable, traded in the shadows of every major city.

Kiaro had none.

The goblins he’d killed had been too weak to leave cores behind. Only a shaman or a champion would drop something valuable.

He ran a hand through his hair.

I need cores just to keep using the system. And stronger cores to grow faster.

The world had given him a key to break every rule—but the lock was still there. Just… different.

---

Morning arrived too quickly.

Kiaro met Renn at a small tavern on the edge of the slums. The place was called The Broken Shield—a fitting name for a gathering spot where low-rank hunters with shattered dreams came to drown their sorrows.

Renn was already sitting at a corner table, nursing a cup of cheap tea. He looked up as Kiaro approached.

“You look terrible.”

“Didn’t sleep,” Kiaro admitted, sliding into the seat across from him.

Renn raised an eyebrow. “Regretting our deal already?”

“No.” Kiaro glanced around to make sure no one was listening. The tavern was nearly empty at this hour—just a few tired D-ranks nursing hangovers and a sleeping bartender behind the counter. “I learned something new about… my ability.”

Renn leaned forward, eyes sharp. “What kind of something?”

“It needs fuel.” Kiaro kept his voice low. “I can’t just grow forever. Every time I use my power or increase my stats, it consumes something called Energy. When Energy runs out, I’m useless.”

Renn’s expression darkened. “How do you get more?”

“Rest. Or…” Kiaro paused. “Monster cores.”

A long silence stretched between them.

Then Renn let out a low whistle. “Monster cores. Of course. The one thing every low-rank hunter can’t afford.” He set down his cup. “Even an F-rank core goes for fifty silver. A D-rank core? Three hundred. And you’re telling me you need them just to function?”

Kiaro nodded.

Renn rubbed his face with both hands. “I was hoping you’d found a miracle. Not a new kind of debt.”

“It’s still a miracle,” Kiaro said. “I can grow. No one else can. But I need a way to get cores without spending money I don’t have.”

Renn was quiet for a moment. Then his eyes flickered with something—reluctant knowledge.

“There’s a black market,” he said quietly. “Under the old arena. Hunters sell cores there illegally. No questions asked. But the prices are even higher than the official guild exchange.”

Kiaro’s jaw tightened. “How do I get in?”

“You don’t just walk in.” Renn glanced at the bartender, then back at Kiaro. “You need a broker. Someone who vouches for you. And brokers take a cut.”

“Do you know one?”

Renn hesitated. Then he sighed.

“I know someone. But she’s dangerous.”

---

An hour later, Kiaro found himself standing in front of a rusted door beneath the Aurelios arena.

The air smelled of mold, old blood, and decay. Faint echoes of footsteps came from above—the arena’s main floor, where hunters sometimes sparred for coin and glory. But down here, in the catacombs, a different kind of business thrived.

Renn knocked three times. Paused. Knocked twice more.

A small slot slid open. A pair of cold, gray eyes stared out from the darkness.

“Renn,” a woman’s voice said. Flat. Unimpressed. “You’re still breathing?”

“Barely,” Renn said. “I brought someone. He wants to buy.”

The eyes shifted to Kiaro. Scanned him from head to toe.

“He looks like an F-rank.”

Kiaro didn’t flinch. “Looks can be deceiving.”

A long pause. Then the door creaked open.

The woman behind it was tall, lean, and hard-faced. Maybe thirty years old. Her hair was cut short, and a jagged scar ran from her temple down to her jaw. She wore no hunter badge, but Kiaro could feel it—a presence that said I’ve killed before and I’ll kill again.

“Name’s Mira,” she said. “I run this market. Renn says you want cores. What rank?”

“F to D,” Kiaro said. “As many as I can get.”

Mira’s lips curled into something that wasn’t quite a smile. “You got coin? Because F-cores are fifty silver each. D-cores are three hundred. And I don’t do credit.”

Kiaro reached into his pocket and pulled out a small leather pouch. Inside was everything he had—seventy silver coins, saved over years of odd jobs and scavenging.

Mira glanced at it. “That’ll get you one F-core. Maybe two if I’m feeling generous.”

One core. For almost all his savings.

And the system needed cores constantly.

Kiaro felt the weight of the trap closing around him.

“I don’t have that kind of money,” he admitted.

Mira shrugged. “Then we’re done.”

She turned to close the door.

“Wait.”

Kiaro’s voice stopped her.

“I don’t have money,” he said. “But I can clear portals. Faster than most. If you give me cores on credit, I’ll pay you back with interest. Or…” He took a breath. “I’ll bring you better cores. Higher rank. More valuable.”

Mira turned back slowly. Her eyes narrowed to dangerous slits.

“You’re an F-rank. You couldn’t clear a D-rank portal if your life depended on it.”

“Try me.”

The silence stretched.

Renn shifted uncomfortably beside Kiaro but said nothing.

Then Mira laughed—a short, sharp, humorless sound.

“You’ve got guts. Stupid guts, but guts.” She crossed her arms. “Alright. Here’s my offer. I’ll give you two F-cores upfront. No charge. In return, you bring me one D-core within two weeks. Not from the market—from a portal you cleared yourself. If you fail…” Her eyes turned to ice. “I’ll know. And I’ll make sure no one in the underworld ever sells to you again.”

Ding.

[Optional Quest: Mira’s Debt]

Objective: Deliver one D-rank monster core to Mira within 14 days.

Reward: Access to black market, +200 XP, Mira’s Favor (???)

Penalty: Black market permanently locked. Reputation loss in underworld.

Kiaro read the screen.

Then he nodded.

“Deal.”

Mira reached into a locked chest behind her and pulled out two small, faintly glowing stones. Each was the size of a marble, pulsing with a dull red light.

“F-rank cores. Goblin-grade. Don’t waste them.”

Kiaro took them carefully. The moment his fingers touched the first core, the system flashed.

[Energy +25%]

[Current Energy: 59%]

Just one core gave me a quarter of my bar back.

He looked at the second core.

[Energy capacity increased by 5%]

[New Maximum Energy: 105%]

And using it for capacity instead of recovery…

He had a choice now. Restore or expand.

He pocketed both cores without using the second. Better to save it for later.

“Two weeks,” Mira said. “Don’t be late.”