The Protagonist's Sister Is Actually The Strongest

“THIS IS ALL I HAVE!”

As the Heavenly Demon roared, his energies converged, compressed, and surged into his fists. The Demon’s eyes widened in pure horror and fear.

“{Abyssal Cursed Demonic Seal Release}: {Heavenly Path of Demonic Ascension}!”

All that power swirled and condensed as he drove his fists into the King of All Evil, piercing through flesh, bone, and soul itself. Explosions of blinding white and golden light intertwined with black and purple darkness erupted endlessly across the monster’s body.

His roar shook the heavens as his very soul burned with the passion for his own path and the deep love he held for those he treasured most.

This world he had once hated so fiercely, the world he had wanted to see burn…

It had become the very thing he now fought to protect.

“How ironic…”

He smiled faintly as his fists smashed through the head of the King of All Evil. The monstrous demon’s body, torn apart and barely held together by muscle and bone, roared back, revealing its true horrifying form.

“YOU’RE NOT… A GOOD PET!”

The monster’s flesh constantly regrew, bones and muscle reforming at terrifying speed. The Heavenly Demon realized the fiend was absorbing hundreds of demonic souls from all those he had slain, using them to fuel his endless power.

Yet even as the massive bony fists hurtled toward him, he did not falter. The world around him began to transform. His memories, emotions, and convictions bloomed into a magnificent black lotus.

“{Heavenly Path of Demonic Ascension Echo}!”

His single eye blazed with crimson light as his soul surged out of his body, punching straight through the gigantic bony fists and taking solid form.

The shape of countless figures appeared.

He was no longer alone…

Several figures stood by his side, guiding his every strike:

The compassionate smile of his mother.

His father, smiling at him with pride.

His big sister, always nagging yet now trusting him completely.

His big brother, still guiding him even now.

The slaves he had befriended, and the many he could not save.

The demonic cultivators who had become his rivals and friends, despite the lonely path he once walked.

The Heavenly Empress, Anna, and Song.

And even Yin Sheng, Wai Tian, and all the demonic cultivators who had joined him.

“This is… like Anna’s Myriad Self?!”

His eyes widened as he realized his power had ascended to a level similar to hers. His attacks multiplied into dozens. His fists and claws tore relentlessly through the bony arms of the King of All Evil.

RUMBLE!

“NNNGGHH?! I-IMPOSSIBLE! THIS IS… IMPOSSIBLEEEEE!”

The King of All Evil, Lucifer himself, was being overwhelmed by the power and conviction of a single “mortal.”

Crack… crack…!

His arm began to shatter, exploding into pieces. His regeneration failed as the assault continued, ripping into his torso and head.

“YOU BASTARD…! DON’T THINK… YOU WILL GET AWAY… FROM THISSSSS!”

The convergence of memories, power, and unbreakable willpower erupted from the Heavenly Demon’s entire body, disintegrating Lucifer’s flesh and bones. Even the Cosmic Demonic Soul of the Original Sin wavered, cracking despite his overwhelming strength.

“{Ultimate Pinnacle}!”

BOOOMMM!!!

As Lucifer screamed in horror and disbelief, half his body was blasted into ashes. In his long existence, no one had ever wounded the King of All Demons, the Original Sin, the first creation of the Father of Heaven.

Crack… crack…!

CRACK!

“M-My soul…?! This damn bastard…! UUGGH…!”

Darkness and light engulfed him completely in the explosion. The heavens trembled and the seas below evaporated in an instant. The Heavenly Demon’s attack was so powerful it nearly split the world in two.

Yet it did not.

In the past, fueled by darkness and evil, his power might have shattered everything. But now, though immensely strong, his attack carried a strange gentleness.

Still, the residual force that reached the sea along with the Demon’s body triggered an even greater explosion. So much seawater evaporated that the ocean floor was briefly exposed.

Anna, the Heavenly Empress, and Song, who had finally regrouped, rushed toward the origin of the explosion. They fought through hundreds of demons to reach the battlefield high above the skies.

“That’s…! Isn’t that the Demon you talked about, Anna?!” Song asked. “Father did it! He defeated him!”

“T-That’s…! That energy…!” Anna’s eyes widened as she recognized the aura of her nemesis. “It really is him… Lucifer…!”

As they watched the monstrous figure fall into the ocean, most of his body gone and generating countless ripples, the Heavenly Empress turned her gaze to the Heavenly Demon.

“Dear! You did it! That was incredible! You actually did it!” She smiled, her voice overflowing with joy at his astonishing victory.

“Dad!” Song cried.

“Are you alright?!” Anna asked.

The trio reached the Heavenly Demon, who floated silently in the sky, gazing down at the ocean with his single eye.

“I… I did it…”

His voice was dry and exhausted. He slowly turned to his beloved and his two children, offering a faint smile. Dried blood covered his cracked black beak.

“You could have waited for us, you know?” Anna sighed. “Couldn’t you have stalled for time or simply run? There was no need to fight so desperately…”

She stopped mid-sentence, her entire body suddenly paralyzed. Tears welled up in her eyes as she stared at him up close.

“Dad, that was amazing! What technique was that?!” Song asked in disbelief. “Can you teach it to me later, once everything is over?!”

“Song…” The Heavenly Demon barely registered the words. “I’m so happy… you’re… my son…”

“E-Eh? Why say that out of nowhere?” Song wondered. “Are you…?”

“Hey, let me—Ahh! No!” The Heavenly Empress rushed to his side to heal him, only to scream in horror at what she saw.

There was a massive hole in his chest and several more through his stomach. He was missing one leg, and both arms were shattered.

His soul was fading away.

“Hue Xian… Thank you… for… loving me.”

Hue Xian reached out, but his body slipped from the sky and plunged into the sea below.

“NO!”

Anna was the first to scream, rushing after him.

“FATHER!”

Song cried out in terror, following close behind.

Yet the Heavenly Empress remained frozen, staring at her hands now stained with the Heavenly Demon’s blood.

“Please don’t die! Please don’t die! Please, please!”

Anna reached the Heavenly Demon as his body floated on the cold sea. He had no heart. He was not breathing. His lifeforce was nearly gone, and his soul was vanishing.

He was unconscious.

No one wanted to admit it.

But the Heavenly Demon was dead.

“FATHER! A-ANNA! WE HAVE TO HEAL HIM! MOM! PLEASE COME HERE! MOM!”

Song screamed in horror as he hugged his father. Anna’s hands trembled violently. She activated her healing powers at full strength and began burning through her own lifespan, year after year, in a desperate bid to bring him back.

“MOTHER!”

Song’s cry finally snapped the Heavenly Empress back to reality. She flew down at once, channeling every ounce of power and injecting him with all the power of Hope she could muster.

Yet even as his chest healed and his wounds closed, his body remained motionless and lifeless.

“I-I can revive him! I can bring anyone back with this power! I can do it! I can change this…! I can change this! I CAN…! I CAN…!”

Anna trembled, crying uncontrollably as she sacrificed the long lifespan she had gained through her ascension.

A gentle hand suddenly grasped her arm, stopping her before she could kill herself.

“Anna… Stop,” the Heavenly Empress said softly, tears streaming down her face.

“A-Ah…! No…! I…! NO! I don’t want to stop! I have to save him! I…!”

“I’m… sorry…”

“A-Ahh…! Dad!”

Anna broke down completely, hugging the Heavenly Demon alongside Song. Their tears fell onto his cold body.

The Heavenly Empress could hardly process what was happening. Despite trying to stay calm, her own tears would not stop.

Yet she knew that now was not the time to mourn her beloved.

The monster he had tried to kill still lived.

Its shadow loomed over them as its malformed, aberrant body grew even more monstrous.

“Ahhh, what a pity…! He could have been… such a good pet…!”

As the monster spoke in a cold, unfeeling voice, the Heavenly Empress glared at him with more anger than she had ever felt in her entire life.

“I’ll kill you.”

In that moment, the Heavenly Empress chose to walk the Demonic Path.

Lucifer simply smiled with his many mouths.

“Heh… You’re a cute birdie too… Would you like to become my pet~?”

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