The System's a What?!

The morning air was crisp, the sun barely peeking over the horizon when Jin-woo received a message from Po.

Po: "Yo, Jinbro 2 (Jinho). We're gonna be gone for a little while. Don't wait up. 😜"

Jin-woo stared at his phone, eyebrows twitching. "He really added a smiley…"

Before Jinho could bombard them with calls about guild business, Jin-woo met up with Po, both of them staring at the ominous red key in Jin-woo's hand.

Item: Key to the Demon's CastleRank: ADescription: A key to the Demon Castle. Beware the flames of hell.

Po squinted at the description before deadpanning, "Your System's a pyromaniac."

Jin-woo blinked. "…What?"

Po waved a hand dramatically. "It just had to give you a key to Hell's front door. Why not an Ice Castle? Maybe a water dungeon for variety? Nooo, it's gotta be fire and brimstone. It's like the System took one look at you and went, 'Yep, this guy needs to burn.'"

Jin-woo sighed. "Are you done?"

Po grinned. "Nah, I could keep going. But I'll save it for later."

Jin-woo rolled his eyes, twisting the key in the air. The moment he did, a swirling crimson portal burst into existence before them, heat radiating from its core. The air shimmered as if even reality itself was hesitant about this place.

Po took one glance at it, then suddenly spun around and slapped his hands over Jin-woo's eyes.

Jin-woo flinched. "What the—Po?!"

"Shhh. Just trust me."

Jin-woo stiffened. "What are you—"

"I want you to guess what's in there," Po said, grinning wickedly.

"…Are you serious?"

"Dead. C'mon, I'll give you three hints."

Jin-woo pinched the bridge of his nose. "Fine."

Po held up a finger, despite the fact that Jin-woo couldn't see. "One: It's got three heads."

Jin-woo frowned. "Hydra?"

"Two: It rhymes with 'Tree-Bedded Log.'"

"…That's not even a proper hint."

Po's grin widened. "Three: You definitely don't want it as a pet."

Jin-woo's jaw tightened. He already had a sinking feeling in his gut. "...Three-headed dog?"

Po patted him on the shoulder. "Bingo."

Then, in a blur, Po yanked Jin-woo into the portal.

The two landed inside a hellish landscape—cracked, burning earth beneath them, an eerie red glow stretching as far as the eye could see. In the distance stood a massive fortress, built from obsidian and brimstone, its gates sealed tight.

And directly in front of them…

A three-headed beast, its molten-red eyes glowing with menace. Cerberus, the Gatekeeper of Hell, towered before them, its enormous claws digging into the scorched earth.

Jin-woo sighed. "You had to make a pun out of it."

Po clapped a hand on his shoulder. "Listen, man. If we're fighting hellhounds, I have to make a joke. It's the law."

Jin-woo groaned. "Just—move."

As Cerberus lunged, Po effortlessly ducked under its claws, weaving through the attack with ease—dragging Jin-woo along for the ride like he was an annoying younger brother.

"Alright, Jinbro 1 (Jinwoo)," Po said casually, dodging another swipe. "This one's all you. I'm just here for moral support."

Jin-woo grit his teeth. He knew what this meant—he'd have to fight this thing alone.

He readied his dagger, exhaling slowly. "Fine."

Then, the battle began.

Jin-woo vs. Cerberus

Jin-woo dashed in, slashing at one of Cerberus's legs. Sparks flew as his blade met its molten skin, but the damage was pathetic.

The beast snarled and retaliated, nearly tearing Jin-woo apart. He barely evaded, rolling across the scorched ground.

Po, watching from a safe distance, munched on a piece of imaginary popcorn. "Rough start."

Jin-woo glared at him before refocusing. He needed to adapt. His usual attacks weren't working—he had to find an opening.

Then he remembered something.

When he fought Kaska, the Swamp King, he had survived through sheer determination. If he hesitated here, he was dead.

With renewed focus, Jin-woo charged again, narrowly dodging Cerberus's fangs as he leaped onto its back. He drove his dagger into its spine, twisting for extra damage. The beast roared in pain.

"Atta boy," Po cheered.

Jin-woo continued his assault, landing precise cuts while dodging counterattacks. But the beast was relentless. Eventually, one of its claws struck him, sending him flying into a nearby rock.

Po winced. "Oof. That looked painful."

Jin-woo coughed, checking his health. It was low. Too low.

He hesitated for a split second—then clenched his fists.

No. Not here. Not now.

Opening his inventory, he chugged a Full Recovery Potion. Instantly, his wounds healed, his strength returning in full.

Cerberus lunged again—this time, Jin-woo was ready.

He dashed beneath the beast, avoiding its claws. With a single, decisive strike, he slashed its throat open.

The beast shuddered.

Then, it collapsed.

A system notification rang in Jin-woo's ears.

You have defeated the Gatekeeper of Hell, Cerberus!Rewards:

Warden's Necklace

(A-Rank)

(+20 Agility, +20 Sense)

Key to the Demon Castle

(A-Rank)

Cerberus Fang

(Miscellaneous Item)

Jin-woo fell to one knee, exhaling sharply. He did it.

Po walked up, slow clapping. "Damn, Jinbro 1. That was dramatic."

Jin-woo shot him a glare. "You could've helped."

Po shrugged. "Eh, you had it covered." Then, in one swift motion, he snatched the A-Rank Key out of Jin-woo's hands.

Jin-woo blinked. "Po."

Po grinned. "Po? Oh, you mean the guy currently running to the Demon Castle with your key?"

Before Jin-woo could react, Po took off like a bullet.

"YOU SON OF A—"

Jin-woo raced after him, the two of them sprinting towards the massive fortress, their laughter echoing through the fiery wasteland.

The Demon Castle awaited.