The Demon King's Island, where the Demon King lives alongside the monsters.

As one moves past the reefs and advances toward the center, a poisonous mist, as if rejecting all living beings, grows denser and denser.

Going further, the mist suddenly disappears at a certain point, revealing a mountain shaped like an ogre's face—Oniiwa Mountain.

And atop its summit, perched on a sheer cliff, stands the Demon King's Castle.

The castle's imposing presence rivals the palaces where human kings reside.

The Demon King's Castle is a seven-story structure, with countless powerful monsters dwelling within its walls.

The higher one ascends—from the first to the second, then the third floor—the stronger the monsters become. At the deepest part of each floor, near the staircase, stand the Demon King's Ten Fingers, acting as the castle's guardians.

On the top floor, above the sixth, resides the king of the monsters—the Demon King—who is the root cause of the recent surge in monstrous violence across the lands.

Few, even among monsters, have laid eyes upon this figure.

This is because the current Demon King rarely reveals themselves to the public.

Unlike the self-assertive Demon Kings of the past, the current Demon King has delegated nearly all authority to the Ten Fingers, serving as their hands and feet, while they themselves rarely leave the castle.

As a result, only the most trusted members of the right-hand Fingers know the Demon King's true form and existence.

Moreover, many among the Ten Fingers remain inactive.

Unlike the left-hand Fingers, who actively spread fear of the Demon King, the right-hand Fingers, like the Demon King, avoid entangling themselves too deeply with worldly matters.

What the Demon King and the right-hand Fingers are planning remains unknown.

The only certainty is that the damage caused by the monsters continues to grow, and if left unchecked, the kingdoms will be drained to the point where survival becomes uncertain.

"If this continues, monsters will grow stronger, and within a year, human forces will suffer catastrophic losses."

This joint statement, issued by Jennifer, King Vento II of the Kingdom of Ilias, and Radgrion VII, the current Pope of the religious state of Célie, sent shockwaves through public opinion.

Despite the stir, the statement did not unify the human forces completely.

"The Kingdom of Ilias hid the existence of the Hero, Rey, until just recently! How can we trust such a nation, let alone follow its lead?"

The Empire, which narrowly avoided decline thanks to the recent failure of the Ten Fingers' covert schemes, saw its strength preserved. Meanwhile, the Confederation was profiting from increased arms sales due to the surge in monster activity.

Led by these two nations, an anti-Ilias faction emerged, opposing the Demon King's subjugation efforts.

As a result, humanity on the Hendia Continent became almost evenly split. Ironically, conflicts increased, reducing the forces available to combat monsters.

Rey traveled across nations, appealing for cooperation. However, her trail suddenly vanished one day.

Rumors spread: had the Hero abandoned the world? Or was Ilias merely trying to claim glory for itself?

None of these rumors, however, came close to the truth.

—That she was growing stronger to challenge the Demon King.

Near the Demon King's Castle, powerful monsters dominate the land, forming a harsh, unique ecosystem. Even weaker monsters here are of the third rank, while some among the strongest belong to the first rank.

"Gaaaarrruuuuhhh!"

The Storm Wolf alpha, a second-rank monster, unleashed a tornado. The raging wind wrapped around its pack, scattering blades of air in all directions.

"Guaaahh!?"

The Armor Demons, third-rank monsters who had cornered the wolves with overconfidence, were shredded and flung aside, spraying blood.

"Awoooo!"

Following the alpha's command, the Storm Wolves swiftly finished off the remaining Armor Demons.

The wolves rejoiced, feasting on their fresh prey—until they too paid the price for their complacency.

"Aanggyaaaaahhh!"

A first-rank monster appeared: the Adamantite Tyranno, its body sheathed in magic-infused metal. It chomped down on the wolves along with the Armor Demons they were devouring.

The creature's speed outmatched even the nimble wolves, who fell one after another.

"Grrraahhh!"

The Storm Wolf alpha conjured another tornado. The Tyranno advanced through the whirlwind despite the scratches forming on its body, and with one decisive bite, killed the alpha.

In this unforgiving environment—where even second-rank monsters are easily slain—only the strongest can reach the Demon King's Castle.

And then, floating through the air like a balloon, a single turtle drifted gracefully, unnoticed by the monsters below. Using gravity magic, the turtle descended before the Demon King's Castle.

The apex predator of this ecosystem, the Adamantite Tyranno, immediately sensed the new presence.

"Gyaaahhhhooo!"

Its jaws opened wide, ready to devour the turtle. But at that moment—

Six doors materialized in front of the turtle.

They opened on their own, revealing six men and women, along with a griffon.

The Tyranno lunged to swallow them all whole—

"Maria-sama, allow me... Kuro-nagi!"

Hamil, clad in crimson armor, stepped forward. She wielded a massive, scarlet cleaver, its edge almost comically large.

With one strike, the blade, shrouded in dark energy, pierced the Tyranno's gaping maw and tore through its body.

"Gya...ahh..."

The Adamantite Tyranno perished without grasping what had happened.

Hamil turned around after delivering her technique.

Behind her stood the Savior's group, their faces far more resolute than just a few months before.

Bruno, standing at the center, gently patted Ivy on his shoulder before looking around with a quick turn.

"Alright—let's go, to the Demon King's Castle."

Nodding back to Bruno, the Savior advanced toward the Demon King's Castle.

The final battle, upon which the fate of the world rested, was about to begin—unnoticed by anyone.

Nearly three months had passed since we stepped through that door.

We finished the first stage of training, cleared the second without issue, fought hard against a serious Ivy to reach the third stage... and after that, it was nonstop one-on-one combat with her.

A serious Ivy was, as expected, incredible.

But thanks to my efforts, I could now at least keep up with her.

Of course, winning was still another story... but I was truly grateful she was on our side.

Even while sparring with me, Ivy took care of the other Savior members. I sometimes asked how everyone was doing, and I quickly realized everyone was pushing through their own grueling training.

Knowing that everyone was working hard, even from afar, helped me endure the harsh training.

Whether the results paid off... we’d find out soon enough.

Still... I never expected our reunion to happen here, at the Demon King's Castle.

I followed the group, now somehow different, into the castle.

"Please, climb on, boss!"

"...Alright, got it."

Sanshita, with a sharp expression, was more scarred than before. But instead of looking battered, he radiated reliability. He was noticeably larger now and showed no strain carrying me. He had also learned to suppress his magical aura, reducing the leakage of power compared to before. His strength, however, had grown tremendously.

"I'll clear the way!"

Sanshita conjured a magic circle, releasing a single-action spell. Once mere harassment-level attacks now easily shredded even first-rank monsters.

"Brother Bruno and Sister Ivy need to conserve their strength. Clearing the way is our job."

Sanshita ran faster than his old top speed, yet Shannon, Rey, Icicle, Hamil, and even the non-combatant Maria kept pace without breaking a sweat.

Thanks to Ivy's magic, the castle was already mapped out as soon as we entered, allowing us to move straight toward the stairs.

And there, naturally, a monster awaited us.

I thought we could just plow through ordinary monsters... but it wouldn't be that easy.

"Hsssshhh... hsshhh."

The creature was massive, both vertically and horizontally. Its body was covered in a viscous, fat-like substance, and it exhaled green breath through heavy, labored breaths. In its hands, it wielded an iridescent club, clearly built for raw power.

Its dull eyes turned toward us as we approached.

"I... I'm Mash... Demon King's Ten Fingers... Left Fifth Finger... Let's... fight fair and square."

"Bruno-san."

"Leave this one to us."

Maria and Hamil stepped in front of me as I sat on Sanshita's back.

Maria wore a crimson habit I'd never seen before, and Hamil's armor was an upgraded version of his previous suit, blending red and purple hues.

"Alright. I'm counting on you."

I said no more, simply nodding.

Likely, each floor would have another member of the Demon King's Ten Fingers waiting for us. Beyond them, the Demon King awaited.

No matter the order, fierce battles were inevitable.

And if Maria, with her limited stamina, was going to give her all, this was the best time to do so.

As we headed for the stairs, Mash moved to block us.

"I... won't let you... pass!"

The club swung down with astonishing speed, faster than one would expect from such a massive creature—nearly supersonic.

Its shimmering, rainbow-colored club was likely made entirely of mithril.

But none of us felt fear.

Clang!

"Wha...!?"

Hamil intercepted the strike head-on, her body faintly glowing white—Maria's enhancement magic at work.

We slipped past the battling pair and ascended the stairs.

"Good luck, everyone."

Maria's words followed us as we charged into the second floor.