The Heroine is My Stepsister, and I'm her Final Boss

"Meeooowww…"

The sound was fragile at first, a silken thread stretched across the silence, echoing strangely in the vast dead air. The cat's cry did not belong here—soft, domestic, ordinary—yet it cut through the oppressive weight of Hell like a crack in stone. It sat on its haunches, tail swaying lazily, licking its paw as though nothing about this place mattered. Its fur shimmered faintly in the dying light, every stroke of its tongue catching the dim glow, as if the creature were its own lantern.

Lara's voice broke next. It was brittle, tight around the edges, carrying weariness wrapped in steel.

"Well, here we are… what now?"

Her eyes were lifted upward, to the wall that rose before them like the carcass of a mountain. It was no natural cliff, no mere collection of rock. The dark stone stretched on endlessly, its surface marred by scars—vast holes gouged into its hide as though some ancient beast had raked claws across it. The air smelled faintly of ash and old iron.

"…there must be a gate somewhere. We can't climb it," Claire murmured.

Her tone was steady, but her hand unconsciously adjusted the strap of her leather glove, a gesture she always made when nerves pricked at her. The wall radiated a cold authority, as though it had swallowed generations before them.

Eli crossed her arms, gaze narrowing at the black expanse. "Atlas would have destroyed the wall…" she muttered. Her lips pressed thin, arms tightening. She was always Atlas's shadow, haunted by his strength, by what he could do that they could not.

"Can't you girls wait?"

The voice came from behind, low, old, and strained. Merlin's tone had that edge of irritation, the kind fathers use when tired of their children's bickering.

His beard trembled with the sigh that followed. "The soldiers and the mages are observing. It's a wall. And if there is a wall, then there must be a gate somewhere. It is as simple as that."

All three women turned in unison, their gazes piercing him with silent daggers. Of course they knew. They didn't need the lesson. His words reeked of weary authority, the kind he clung to because everything else—their safety, their survival, the trust of gods—was slipping beyond his grasp.

Merlin caught their look, sighed deeper, and lifted his staff. His bones felt heavier than they had in years, and his body swayed with exhaustion. He tried to will himself upward, tried to fly, but the mana here twisted, unruly, like trying to grip smoke. This was not the mortal realm; nothing obeyed as it should.

Even the air tasted wrong. Acrid. Dense. Every breath was a labor.

'Even my magic is crippled here,' Merlin thought bitterly, his mind racing toward the one question that gnawed at him. How did Aurora manage this?

Minutes dripped like molten lead into hours. The silence grew thick, pressing against their ears until even the faint rustle of their own clothing felt too loud.

The soldiers and mages who had spread out earlier had not returned. Their absence became its own presence, a weight of dread pressing against the group's ribs.

The three women busied themselves with the cat. Strange, how they let it charm them, as though by touching its fur they might remind themselves of warmth, of life. Lara scratched behind its ear, Claire coaxed it to chase a string of light, Eli smirked faintly when it pawed her boot. For those fleeting breaths, the wall seemed less crushing, the silence less unbearable.

But time stretched on. And with each passing moment, the absence of sound grew louder, more accusing.

This was Hell. What had they expected? That soldiers and mages could survive here, where even gods tread carefully? The thought rooted itself like thorns in Lara's chest.

"…should we go and check now?" she whispered finally, her voice trembling with the edge of decision.

Merlin closed his eyes. His breath steadied, though his heart did not. He let his mana spread outward like a net cast into poisoned waters. The effort burned; the hostile current of Hell's mana pushed against him, corrosive. He forced it anyway, teeth gritted, sweat running down his temple.

His vision expanded—barely. His spell faltered, its reach stunted, but enough to glimpse the nearest presences. He felt the faint flicker of magic from the mages. But the knights… nothing. No warmth, no life-signs.

Dead silence.

Even within the wall, nothing. No beating hearts, no whisper of breath. The void pressed back, swallowing all. Perhaps there had once been life, but now only corpses… or worse.

Merlin opened his eyes slowly. The fading light made the shadows under his eyes cavernous.

"…no need to worry too much, Lara," he said at last, his voice quieter than before, though heavy as stone. "They are dead. All of them are dead."

The words dropped like iron into their midst.

Lara's eyes widened, blue irises gleaming with sudden fury. Her hand instinctively reached for her sword, steel whispering against its scabbard. Rage flared with grief; her people, her comrades—gone. But Claire caught her shoulder, grounding her with silent strength.

Night was falling now. The air shifted, cooling sharply, carrying with it a stench of rot, of old graves split open. They all knew the rule of this place: when night came, Hell reshaped itself. The dead walked again, and the living sometimes did not.

Some demons, those without divine scars, rose anew each night. Others, blessed—or cursed—by divine wounds, remained ash forever.

Merlin could already feel it, faint threads of divinity lingering in the city beyond the wall. The place was a battlefield where divinity had once clashed, leaving scars that outlasted centuries.

The sky trembled.

Another star fell, burning streaks across the darkness. Then another. And another.

Claire whispered, "Three more…"

Eli's lips twisted bitterly. "How many demi-gods are coming to Hell, for gods' sake?"

The question hung, unanswered.

Until—

<…most of them...>

The voice was smooth, unexpected, spilling from the shadow itself.

They turned, every breath seized in their throats.

From the veil of night stepped a figure. His skin was purpled, glistening faintly in the star-fire glow. He wore a simple brown gown, but it was marred with blood, the stains dark and deliberate.

His face was calm, almost humble, but the moment they saw him, every instinct screamed. This was not merely a man. His presence radiated—no, overflowed—with the residue of Heaven. Residue of divinity.

A demi-god.

Merlin was first to rise, staff angled, voice ringing sharp: "Who are you? Are you the one who killed our people?"

The figure raised a hand, almost lazily. His voice rolled like velvet thunder.

"Shush, child. I am older than you could ever hope to be. Much older."

The weight of those words pressed on Merlin's chest, and inexplicably—shamefully—he fell silent. His own tongue obeyed the command, bound by something more than authority.

The demi-god's gaze shifted to the three women. His eyes were bright, soft, incongruously polite. "And you three," he said gently, "what brings three gorgeous mortals to the realm of Hell?"

Lara stepped forward, her sword unsheathed, its tip gleaming cold. Her pulse roared in her ears, but she held his gaze, defiance in every line of her body.

"Fuck off, who ever you are..."

The demi-god smiled, tilting his head. There was almost admiration in his expression. "Oh… you do not fear me. You are different, child. I sense something in you, same like that mortal name Atlas ."

Her voice was steady, though fire burned in it. "…of course I am. I am his sister. I am his blood.

And...we don't speak with murderers. Are you the one who killed. my. people?"

The blade rose higher, until it hovered at his neck, silver quivering with her fury.

Merlin tensed, spells half-formed at his fingertips. His priority was clear: protect Lara. He could not afford even a flicker of Atlas's wrath if she fell here.

The demi-god stepped forward. The sword pressed into his chest, but it did not pierce. His skin was firm as iron, yet warm as flesh. Lara strained, teeth clenched, but the blade refused to bite. With each step, she was pushed back, as though her defiance meant nothing.

His voice dropped, no longer velvet but venom.

"I do not care if they were your people. They attacked me first. And if you make the same mistake…"

His eyes narrowed, power leaking like flame from a cracked vessel.

"…I will do the same as I did to them.... Squash you into a bloody pulp."

The words scorched the night, leaving silence in their wake..

Merlin smiled when he heard those foul words. Not the smile of amusement, nor the sly grin of a trickster, but the kind of smile that leaks from a wound too deep to heal.

"Ohhh… demi-gods," he whispered, his tone thick with loathing. "That's why. That's why I hate you lot."

The word rolled from his tongue like venom. He hated them all—their arrogance, their gilded titles, their divine inheritance worn like stolen crowns.

He hated them, and more than that, he hated the gods that spawned them, those absentee tyrants who sat upon high thrones and threw bones of power to their bastard children.

Hatred burned in him like a second heart. Pure hatred. Not the kind that flared in a moment and then guttered out. No, his hatred was carved in stone, layered in centuries, cooled and reforged like tempered steel.

He remembered—flashes of golden temples, the thunder of false hymns, the way the demi-gods strutted like suns given flesh. He remembered how mortals bowed to them, kissed their feet, called them saviors. And in every bow, in every kneeling prayer, he saw chains.

"utter Filth," he muttered.

******

Sorry guys, I'm really busy these days, so the next chapter will come tomorrow.