Journey to the underworld: How I became the demon king

The air in Purgatorio grew heavier as I sat, exhausted from my first trial. My body trembled, every fiber aching from the encounter with the skeletal creature. Yet, there was no time to rest. The figure appeared again, its hollow gaze piercing through the dim haze.

"You survived," it said, almost as if in disbelief. "Barely."

I frowned, wiping ash from my face. "What now? Another monster to throw at me?"

The skeletal figure raised its bony hand, and suddenly, the oppressive air shifted. Before me appeared a translucent screen, faintly glowing, with strange runes and text I couldn't read.

"This is your Vessel System," the figure said, its voice echoing. "A gift and a curse. Use it wisely. It will house your weapons, aid your growth, and test your resolve. But remember, power is not free—it must be earned."

The screen shimmered, its text now readable:

[Vessel System Activated]

- Inventory unlocked

- Skills: Locked

A strange warmth surged through my chest as a new notification appeared:

[Weapon Acquired: The Eminence]

At that moment, a sword materialized in my hand. It was unlike any blade I had ever seen—pitch black, with veins of crimson running along its surface, pulsing like a living thing. The hilt was adorned with intricate carvings of serpentine figures, their eyes glowing faintly red.

"The Eminence," I whispered, feeling its weight. It wasn't heavy, but it radiated an intimidating aura, as though it were alive.

The skeletal figure observed me silently before speaking. "The sword is bound to you now. You may store it within the system, summoning it only when needed. Carrying such a weapon openly would attract enemies far beyond your current strength."

With a thought, I willed the sword into the system, and it vanished in a flash of crimson light. The screen displayed:

[Weapon Stored: The Eminence]

A sense of relief washed over me, but it didn't last.

"Your next trial begins now," the figure said, its tone as cold as ever. "You will learn to control a fragment of your power. The Demon King's candidates wield abilities far beyond mortal comprehension. You, however, will start with soul control."

"Soul control?" I echoed, confused.

The figure raised a skeletal hand, and the ground trembled. A pale blue wisp of energy emerged, swirling before me. "This is a soul—an essence of the dead. Harness it, bend it to your will, and give it form. Fail, and it will consume you."

I stared at the wisp, my chest tightening. "And if I succeed?"

"Then you will have an ally," the figure said. "But tread carefully. Souls are not mere tools—they carry memories, emotions, and, sometimes, vengeance."

Taking a deep breath, I extended my hand toward the wisp. It resisted, writhing and twisting as if trying to escape. My mind raced with doubt, but I focused, willing the energy to obey. Slowly, it began to take shape.

The pale light condensed, forming a humanoid figure. A girl emerged, her translucent body solidifying until she stood before me, fully formed. She had long silver hair that shimmered faintly and piercing blue eyes that glowed like the wisp from which she came. Her presence was both ethereal and commanding.

"I... am Aurora," she said, her voice soft but resolute. "Who dares to summon me?"

I hesitated, unsure of what to say. "I'm Kuro. I—"

Before I could finish, Aurora's eyes narrowed. "You're weak," she said bluntly. "Barely worthy of my presence. Why summon me if you can't even protect yourself?"

The skeletal figure chuckled. "She speaks the truth. But that is why she's here. Aurora, you will train him. Teach him the basics of survival in Purgatorio. Your rank is A—do not go easy on him."

Aurora crossed her arms, eyeing me critically. "Fine. But if he can't keep up, don't blame me when he collapses."

The skeletal figure's hollow eyes glimmered faintly. "Consider this a gift, Kuro. She is your first ally—and your first challenge."

As the figure vanished, Aurora turned to me, her gaze cold and unforgiving. "Lesson one: If you want to survive, stop looking so scared. Fear won't save you. Now, let's see what you're made of."

The ground beneath us shifted, forming a circular arena of jagged rock. Aurora summoned a translucent blade of her own, its edges glowing faintly blue.

"Prepare yourself," she said, a smirk playing on her lips. "Because I won't hold back."