The Protagonist's Sister Is Actually The Strongest

Their hearts, souls, and bodies became one.

Through the combination of their Auras and Powers, and the alignment of their thoughts, emotions, ideals, and mutual love.

When the Heavenly Empress embraced the darkness she had sealed this entire time within her, which had been formed by only embracing the good things, without letting her mind attain true balance and accepting that she is also filled with flaws and that “complete goodness” doesn’t exist.

And when the Heavenly Demon began to regret the bad things he had done, finally embracing the good that was being born within him thanks to the love of his wife and his son, and also of Anna.

After embracing their other half, each one of them became a complete being, and these two complete beings, upon embracing one another and unifying for the same cause, became one.

FLAAASH!

Their flesh, bones, blood, hearts, and souls fused, becoming a single entity covered with beautiful black and white feathers.

A giant bird-like divine being, with four enormous wings of black and white colors and a majestic and sharp-looking golden beak, with four eyes—two red and two gold.

With four muscular arms and two slender legs, sharp and powerful-looking talons on all six of its limbs, and a powerful presence, it emerged.

After having merged with their counterparts born from the World’s Records, who had already merged together as one, they were able to do it again.

They had never practiced this before, and they didn’t even originally intend to, but…

It happened almost on its own, as if the Heavens willed it.

RUMBLE!

Their Aura of Darkness and Light spread through the skies, changing the color of the heavens above them; the sea beneath disappeared as a domain was instantly conjured the moment their fusion was born.

“They fused?!”

Anna was shocked at the sight as the gigantic proton cannon beam reached their fusion; their four arms moved forward as miniature formations made out of their raw power quickly emerged from their palms.

BOOOMMM!!!

The moment the beam impacted them and a gigantic explosion engulfed their bodies, the smoke dissipated right away, revealing them to be fine, encompassed by an almost transparent bubble of black and golden essence.

The four mini formations they conjured out of the palms of their hands had unified into this powerful combined protective bubble!

“They tanked it!” Song said in happiness.

“They got this…” Anna nodded. “Alright, Song, let’s begin.”

While the fused Venerables fought their demonic son, Anna and Song combined their powers and Auras as well.

They expanded into a large formation as several runes started flying everywhere; Anna started using several materials she had with her.

The Morphin Core that she had obtained from the Rainbow Knights was placed as the formation core, as she decided to use it as a strengthening device.

The formation consisted of three layers: the first layer was a hundred golden runes of the Dao of Souls, the second layer had two hundred red runes of the Dao of Death, and the third layer had four hundred black runes of the Dao of Yin.

Why not Yang? Because Anna needed to focus solely on Yin, the dark side of the perfect harmony, where the element of death and souls existed and therefore, where they would be strengthened the most.

Indeed, this wasn’t just going to the Demon King and taking their souls; Anna and Song had to prepare a large formation they would carry along, one that would allow for a powerful “Heavenly Technique” that would activate, a creation of the Venerables themselves, who were much more experienced than Anna and Song at Soul Manipulation.

“GRAAAAHHHH!”

The Demon King roared, summoning more cannons around his foes and firing dozens of gigantic proton beams at the fused Venerables.

However, the Venerables conjured six floating Heavenly Yinyang Shields and repelled the damage, redirecting it back at the Demon King almost at lightning speed.

BOOM! BOOM! BOOM! BOOM!

The repelled attacks were strengthened with their Heavenly Auras, becoming powerful and deadly; several holes were pierced through the Demon King’s shoulders, stomach, and chest.

Yet the biomechanical monstrosity, their son, was still unyielding, gritting his teeth as foam came out of it, his several red eyes spinning with madness and beastly instincts.

“DIEEEEEE!”

A monstrous voice echoed from him as a massive sword materialized by fusing several mechanical parts that materialized out of nowhere.

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The gigantic one-kilometer-long mechanical blade was just utterly ridiculous, something only a world-destroying threat as a Demon King could manifest.

And yet the fused Venerables faced it with a calm expression on their eyes, concentrating their powers and fusing them.

The Venerables, who had reached a bottleneck before on their own, were finally awakening upon new powers after fusing into a single entity.

The path towards ascension was never something they could walk on their own, but something only achievable through walking together!

“{Divine Venerable Imperial Armament}: {Heavenly Yinyang Palace of Harmony}”

They summoned no weapon or armor, not even a shield, but a majestic, gigantic palace that stretched all the way into the skies behind them.

The palace exuded an almighty heavenly aura of both darkness and light. The fabric of space and time around the palace was being rapidly distorted.

CLAAASH!

When the massive mechanical sword struck the palace, a loud dinging sound spread through the skies; the singing sound released a shockwave, which made the entire mechanical blade…

Crack, crack…!

CRAAASH!

Fall apart into pieces.

“NNNGGHH?!”

The Demon King groaned in pain; the shockwave that destroyed his weapon also spread through his body; mechanical pieces began to rapidly explode out of his flesh as his biomechanical body started undergoing a “cleansing,” its mechanical parts beginning to rapidly fall apart.

“That palace is… an ultimate form of the Yinyang Shield?!”

Anna immediately realized what that palace was; the Venerables had mastered the Yinyang shield’s principles and powers and created something even stronger, a gigantic floating palace that could both protect them and repel damage.

The damage itself was almost inconspicuous and not flashy at all, a small shockwave generated by a sound wave that rapidly expanded and destroyed mostly all electronic materials; anything that ran by circuits and such was decimated.

“RAAAAHHH!”

The Demon King didn’t give up yet, though; although he had grown incredibly weaker than before, he rapidly materialized dozens of gigantic mechanical arms, punching the palace constantly.

TRUUUM! TRUUUM! TRUUUM!

And the palace, in response, released shockwaves that destroyed each gigantic, over three-hundred-meter-big mechanical arm, decimating them into pieces.

“GGRRRHHH!”

The Demon King roared like a beast, growing desperate and frustrated because of the power of his foes and how they were negating anything he could throw at them.

RUMBLE!

The space began to rapidly fragment apart before his rage as the pressure he released was constantly growing larger, demonic energy and electromagnetic energy intermixing.

“SHAAAAHHH!”

With a ferocious, hiss-like scream, the monster opened his jaws and fired a massive beam from his beak, aiming to destroy his foes.

BOOOMMM!!!

The palace’s powerful barrier held on strong, but it was being rapidly pushed back; the beam continued being unleashed nonstop; it was as if the Demon King had endless energy.

Crack, crack…!

Countless cracks started to spread through the palace; it was unable to hold on against so much power at once; the Venerables knew that if they evaded, the beam would hit somewhere on the world’s surface, leaving tremendous damage even if it fell into the sea.

“We must repel this into the skies.”

Their voices were mixed as they spoke to themselves; they held on to the power and essence of the Palace and then began to rapidly transform its shape into a gigantic palace made of mirrors.

“{Heavenly Yinyang Palace of Harmony Arts}: {Silver Lotus Palace of Moonlight Mirrors}”

FLAAASH!

The beam was redirected into the skies as it impacted on the empty air above, dissipating across the stratosphere with a massive explosion.

BOOOMMM!!!

“Haaahhh… Haaahhh… Graaahhh…!”

The Demon King was suddenly beginning to cool down; its entire body was releasing a massive quantity of steam everywhere; its metallic parts were hot red.

“Now!”

The fused Venerables rushed forward, without daring to waste the opportunity at all, and immediately transformed the palace that came alongside them once more.

“We must suppress him at all cost but killing him we cannot!”

Song’s parents reached him at long last; their palace of mirrors turning into golden and black light and then transforming, growing longer than ever before, as gigantic heavenly chains of Yinyang manifested.

“{Heavenly Yinyang Palace of Harmony Arts}: {Heaven-Sealing Chains of Harmony}!”

Their powers converged into a gigantic mass of chains that wrapped around the weakened, cooling-down Demon King, who reacted very surprised as the chains began to coil around his limbs and body, then his beak, firmly closing it.

“GRRRHHH?! GRAAAEEERRRGH!”

It roared while struggling to free itself; its strength was much lower than before after the intense battle, and even though flames were constantly being released from its body, they weren’t as strong as before either.

FLAAASH!

The chains glowed brightly as they continued wrapping around its body like vipers, ultimately shining and then unifying into a powerful golden, black, and white seal containing the power of Hope, the Cursed Marks, the White Void, and the power of Despair all into one.

“G-GAARRGH…?! G-GUEEGH…!”

The Demon King was unable to move at all, only releasing pitiful noises; its giant eyes widening in disbelief, it was completely overwhelmed!

“NOW, ANNA!”

In that moment, Anna and Song were ready, mounting over Fang Shuan’s mechanical form; the two moved the gigantic formation they created together, throwing it towards the Demon King at once.

Their wills, souls, and auras became one as Song and Anna screamed at the same time, activating the incantation of the formation, a necessary step to fully unleash its powers within this world.

“{Heavenly Soul Extraction Formation}: {Three Wheels of Demonic Nirvana}!”

By combining the teachings of both the Heavenly Demon and the Heavenly Empress, Song’s powerful abilities, Anna’s powers, Myriad Self Arts, and even the Morphin Core, the formation wrapped around the body of the Demon King, each wheel spinning around its body, sealing it even further.

“NNGGRRHH?!”

The Demon King couldn’t even open its mouth anymore, and even its eyes were covered by the seal, unable to see what was happening.

Anna, Song, and Fang Shuan rushed towards the Demon King, finally touching his body and reaching his stomach.

“Are you ready, Song?”

Anna asked Song, her eyes shining brightly with hope in them.

“Yes!”

The boy born from the Records of Song, a part of him, but not quite the real him, nodded.

“Fang Shuan, please make sure the ritual is not interrupted! The power of the Morphin Core will empower you even further; if the Demon King fights back, it’s all up to you.”

“Leave it to me.”

Fang Shuan was Anna’s strongest familiar so far, and he nodded the moment she left this task to him.

Why?

Because to fully extract the soul, Anna and Song would be fully concentrated to the point where their bodies would be left vulnerable, falling into a state of unconsciousness.

“Let’s begin!”

She held Song’s hand as the two infused their Auras into the Demon King.

FLUOOOSH!

It felt rough.

It was as if they were trying to dive through incredibly hard and heavy mud.

However, through their combined power, they crawled their way into the Demon King’s deepest parts.

A gigantic realm of the mind and the soul, an Astral Mindscape.

Anna’s and Song’s souls appeared completely naked here; their equipment and weapons weren’t with them.

“T-This is… the Soul of the Demon King?!”

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