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

The third layer of Hell stank of stone sweat and scorched marrow. Its walls were jagged like teeth, forever damp with an ooze that glimmered faintly under the red glow of torches.

Heat pressed down in waves, not the clean heat of fire but the heavy breath of something alive, something watching. Even silence here had weight.

Atlas walked with measured steps, his cloak dragging shadows behind him. His hand rested briefly on the door of obsidian carved into the rock. Beyond it waited Samiel, the priest. Only one soul within, no choir, no guards, no audience of the faithful. Just two men. Two voices. Two paths that could sunder or unite the future.

He pushed the door. Stone groaned open.

Inside, Samiel stood, clutching the small, timeworn book against his chest. The book was bound in cracked leather, pages yellowed, its spine softened by centuries of trembling hands.

The words inside were prayers older than kingdoms, recited until memory itself wore grooves in the tongue. Samiel's lips moved even now in silent mutter, as though the holy syllables could steady him before the figure entering.

Atlas looked at the book and felt something between pity. He gestured. "Come, Samiel. To the view."

The priest obeyed, hesitant. They walked to the far wall where a gap in the rock revealed Hell itself stretching beyond—a vast landscape of black chasms, rivers glowing molten like veins of a burning god, and in the distance, towers of bone like the ribs of titans. To mortals it was horror. To them, it was home.

Atlas's voice was low, weighted. "Tell me, Sameil. Are you really....really ready to be led?"

Samiel's fingers clutched tighter at the book, as though it alone kept him upright. His eyes, lined with exhaustion and devotion, lifted to Atlas. And he nodded. Heavily. Each movement of his head was a vow. "Every command, my lord. To the bone. Until I perish."

Atlas smiled. A small, patient smile, almost gentle. He extended his hand. "Then give it to me."

Confused, Samiel held out the book. Atlas took it, weighed it in his palm. So light for something worshiped, so fragile for something eternal. He studied the cover, the cracks, the faded ink. Then, without warning, he cast it outside, the gapping hole.

The book falling through the air, its page flapping as it perished in the warm air.

Samiel gasped as though stabbed. He staggered forward, hand half-reaching. "Why?" His voice broke, torn between anger and grief. "Why throw away the words of God?"

Atlas turned to him, unshaken. "Because they were not the words of God."

Samiel froze, trembling.

"The first prophet laid bare his understanding," Atlas continued, voice steady, echoing off the walls like carved scripture. "The second prophet laid bare his. Each built upon the other, each spoke in fragments, in half-seen visions. And I…" He drew something from within his cloak, and light caught on its cover.

A new book.

Black leather polished to sheen, embossed in gold that glowed faintly as if alive. At its center: a single symbol. The letter A.

Atlas held it forward. "I will do the same. No—more. I will complete what they began."

Samiel stared, breath shallow. He reached, then pulled his hand back, fear burning through his faith. His lips trembled. "Then… Ureil was right? What he said about you....how the almighty now speaks through....you?"

Atlas's smile vanished. His eyes sharpened like blades. "You still doubt me?"

The priest's face drained of color. "No—no, never!" He dropped to his knees, bowing low, trembling. His voice broke into desperation. "Forgive me. I kneel. I believe. I serve."

Atlas placed the book in his hands. "Then rise, Pope ....Samiel."

Samiel's head jerked up, eyes wide with disbelief. His throat constricted. "P—Pope?"

"Yes." Atlas's voice was thunder now. "The power to anoint rests not with absent gods who abandoned you. Not with corrupted men who betrayed you.

I heard The last pope turned to the demons. That seat lies vacant. I proclaim you the new one. By my word, by my faith, by my will—you shall lead them."

Samiel clutched the book as if it were his own newborn child. The cover burned faintly beneath his skin, not painfully but insistently, as though alive. He could not look away from the golden A. His breath shuddered. "But… only the Almighty Himself may—"

Atlas cut him off. "The Almighty has not spoken in a thousand years. The Almighty did not stop the corruption of your pope. The Almighty did not shield you when the demons came. But I am here. I act. I lead. Through him."

The words cracked through Samiel's soul like hammers on glass. Something inside him broke, something else reformed. He bowed low again, pressing the book to his forehead. His whisper was almost a sob. "Then I follow. Forever."

The air in the chamber shifted. The book seemed heavier now, not in weight but in presence. The gold shimmered faintly, as though it breathed with Samiel's own lungs.

Atlas stepped back, satisfied. The Book of Acclaim had found its bearer.

.

.

Later, in a hidden chamber carved deeper into the rock, Atlas met with the elder, Azazel and with Aurora herself. The room was round, domed, lit not by torch but by veins of molten stone running through the ceiling like rivers of fire. Shadows licked their faces, alive with the heat of Hell's veins.

Azazel knelt immediately, as he always did, his wings folded in humble reverence. Aurora stood, arms crossed, her presence like ice cutting through the heat. Her silver hair shimmered faintly in the glow, and her eyes, always piercing, held curiosity more than doubt.

Atlas placed the Book of Acclaim, the new upgraded book, the second version of the damned, upon the stone table in the center. Its gold symbol gleamed brighter here, as though it fed on their attention.

He spoke. "The fallens are scattered. Their faith fractured. Their leaders weakened. But with this"—he touched the cover—"they will unify. They will follow."

Azazel bowed lower, forehead to the stone. "....Glorious."

Aurora tilted her head, lips curving faintly. "And what will you have them follow into, Atlas?"

Atlas's gaze lifted to her, calm, unwavering. "Into power. Into freedom. Into destiny, whatever their faith desires...."

"And after?" she pressed.

His words grew heavier. "One day, they will join the demons."

The chamber went silent.

Azazel gasped, trembling with awe. "You… would bind the fallen with the demon kin? Such a thing has never been spoken."

Aurora's eyes widened briefly, then narrowed, calculating. "You would risk their faith, their identity, their very essence?"

Atlas spread his arms, voice swelling. "The Almighty abandoned them. The demons at least remain. Their kings have power. Their armies endure. The fallens drift, lost between Heaven and Hell. But united under me, they will not just survive—they will conquer, you all will conquer, from hell, to the...." He voiced pointing his finger up.

Azazel's voice cracked with zeal. "A vision....A vision worthy of eternity!" He pressed himself flat to the ground, worship incarnate.

Aurora was slower. She studied him, silence stretching long. Then she smiled, faint but genuine. "fuck....You astonish me again, Atlas. You speak heresy with the tongue of prophecy. And it feels…so fucking inevitable."

He stepped closer to her, close enough to see the fire reflected in her silver eyes. "Then stand with me, Aurora. Lead them before me. Prepare the way."

Aurora's smile widened, half admiration, half challenge. "And when the demons see you as rival instead of savior?"

"I will not be rival." His voice cut like iron. "I will be their faith as I am theirs."

The words hung. The molten ceiling pulsed. The air felt heavier, as though the stones themselves bore witness.

Azazel rose slightly, trembling, his voice hoarse with reverence. "Tell us what must be done."

Atlas turned to them both. "Aurora—you will gather the demon kings. Lidia among them. Speak my name, plant the seed. Let them believe they lead, but pave the path for me.

Azazel—you will bend the elders, root their loyalty deeper with every sermon. And Samiel—he will carry the book. My book. The words will spread like fire, whisper by whisper, until it consumes them all."

Aurora inclined her head, a queen acknowledging a king. "As you command."

Azazel pressed his lips to the stone, tears shining in his eyes. "Blessed be the damn....sorry, blessed be the Acclaim."

Atlas closed his hand on the book's cover, feeling its heat pulse like a second heart. He whispered, almost to himself, almost to the walls.

"Not the Lord's will. Not the Almighty's. Mine."

The symbol A glowed brighter.