Puyah World, Western Continent.

This was a world of many races: humans, elves, demi-humans, beastfolk, demons, and more…

Since ancient times, the demons and the other races had been bitter enemies, constantly at odds with one another.

Ten years ago, a demon appeared in the Kingdom of Kaida and built a demon castle in Wailing Canyon, to the south.

The Kingdom of Kaida was a human realm. How could it tolerate a demon appearing on its own territory?

As soon as the Queen heard the news, she issued a bounty calling for the demon’s subjugation and recruited powerful Heroes to defeat the Demon King.

What was a Hero? They were blessed by the Goddess and possessed unique talents beyond the reach of ordinary people. They were born strong.

And yet, ten years later, this demon had become no stepping stone to human fame and fortune. Instead, their infamy had spread far and wide, earning them the name “Prideful Demon King.”

The bounty grew richer with every passing year, but no one dared set foot in the Demon King’s domain anymore.

At the end of June each year, a strange celestial phenomenon appeared: the Crimson Moon, also known as the Red Moon Goddess’s sacrificial day.

There was a little-known secret about this day: half-breeds grew weak, and in severe cases, could even lose the powers they possessed.

Deep within Wailing Canyon.

Towering mists shrouded the area. Through them, one could just make out a massive, imposing structure—the Demon King’s Castle, a place that struck fear into the hearts of many human warriors.

Beneath the Crimson Moon’s light, the Demon King’s Castle looked even more sinister.

Inside the castle.

The Demon King’s Castle was utterly silent. There wasn’t a trace of life to be seen.

In the grand meeting hall, a tall figure clad from head to toe in deep-black armor sat alone upon the throne, a symbol of status and authority.

His name was Luxiu, and he had another widely known title: the Prideful Demon King.

“The Crimson Moon… This damn moon, this damn Red Moon Goddess! One day, I’ll knock that moon right out of the sky and make the damn thing part of my collection.”

Luxiu gazed up. His eyes seemed to pierce through the ceiling and catch sight of the full moon above, glowing crimson in the heavens.

His murmured voice was clear and melodious. It was hard to imagine that it belonged to a Demon King.

Luxiu had a secret: he wasn’t a pure-blooded demon, but a half-breed born of a human and a demon.

In other words, when the Crimson Moon appeared, he lost all his powers.

It was a fatal weakness, and Luxiu didn’t want anyone to learn his secret.

So on the day the Red Moon appeared, he made a point of sending his subordinates away from the Demon King’s Castle, leaving himself in command of no one.

That was why he was the only one in the enormous Demon King’s Castle.

“Having no powers makes me feel so unsafe. Surely no foolish humans will come after me today, right? Hmph. On the Red Moon, the monsters living in Wailing Canyon go berserk, so nobody can get near this place. Besides, I had my subordinates block the way in… I’ve got every angle covered!”

Without his powers to rely on, the Prideful Demon King had grown a little wary. He knew exactly how many humans wanted to take his head and make a name for themselves.

Perhaps he felt unsafe. Or perhaps sitting alone on the throne had simply bored him.

Luxiu made his next move.

With some effort, he took off his black armor and let his body breathe in the fresh air.

And so, Luxiu revealed the true appearance he’d never let anyone outside the castle see.

A handsome face, short silver-white hair, red eyes, and a slender figure.

It was hard to imagine that this harmless-looking, even lovable boy was the Demon King of legend!

“Much better. I’m heading back to my room for a good, long sleep. Tomorrow, I’ll be the fiercest, most evil, strongest Demon King all over again!”

After taking off his armor, Luxiu decided to give himself the day off!

He made his way back to the Demon King’s bedroom with a light step, flopped onto the big bed, wrapped himself in the blankets, and drifted off to sleep.

He had no idea that a party of Demon King slayers had arrived at Wailing Canyon.

The outer reaches were crawling with monsters. Ordinary people wouldn’t dare go near, or they’d be risking their lives.

“Crack!”

A tall figure in white armor swung a greatsword, cutting down every last one of the ugly, savage monsters.

“Sister Xiya is amazing. No wonder she’s the Sword Hero. I wish I could be just like her…”

Nearby, three girls waited at ease. One of them—a soft-spoken girl with snowy-white hair and a healer’s robe—watched the swordswoman slay monsters with admiration.

“There are plenty of valuable parts on these monsters. Kill them if you have to, but don’t chop them into mince! What a waste. That’s money!”

A red-haired girl grumbled. The fox ears on her head twitched with her mood.

“Little Xiya, don’t waste time on these monsters. We still have a Demon King to defeat.”

A beautiful, curvy big sister with golden hair and green eyes waved to the swordswoman.

“Understood.”

Xiya shook the blood off her greatsword and led the party deeper into the canyon, searching for the Demon King’s Castle of legend.

Anything that got in their way was cut down by Xiya’s sword. No exceptions.

“Sister Luna, can we really defeat the Demon King? Legend says she’s undefeated—that no one has ever beaten her.”

The youngest member of the party, Liliya the healer, asked the golden-haired big sister anxiously.

“Don’t worry. We’ll all become heroines who defeated the Demon King.”

Luna was the party’s seer. She brushed back the golden hair by her ear, revealing a pair of delicate pointed ears—the mark of the elves.

She made the promise with such confidence that the uneasy Liliya began to feel a little less nervous.

“I can do without the empty title of heroine. I just want the treasure inside the Demon King’s Castle. That evil Demon King must’ve plundered a lot of valuable things.”

Sarah chimed in. She was the party’s mage, as well as a demi-human.

“We’re here.”

Xiya, with black hair, black eyes, and delicate features, spoke calmly, her expression stern.

The outline of the Demon King’s Castle came into view directly ahead of the slayer party.

In an instant, the party members wore a range of expressions: nervousness, excitement, greed, hatred…

Their months-long journey to defeat the Demon King was nearing its end.

Would they make a name for themselves, or flee with their tails between their legs? It would all be decided today.

“Stay behind me.”

Xiya, the Sword Hero and the party’s leader, gave the order.

The four of them set off for the Demon King’s Castle.

The journey was peaceful. Not a single obstacle appeared.

“Luna, you said the Demon King would grow weak during the Crimson Moon. So why isn’t there even one officer on guard in her territory? I’ve never heard of a Demon King being left with no one at all.”

Perhaps things felt a little too easy to be real. Sarah voiced her doubts in a low tone.

The party’s operations had always been directed by Luna, their seer.

She was the one who’d specifically asked the party to attack the Demon King on the day of the Crimson Moon.

…

Xiya kept her hand firmly on her greatsword and cast a doubtful glance at Luna.

When things seemed too strange, there was usually a reason. It was hard not to suspect that the calm around the Demon King’s Castle was a trap.