The Protagonist's Sister Is Actually The Strongest

The mechanical chest of the King of Steel opened wide, releasing the sound of metal hitting each other, revealing something inside of him, something bizarre that even made Anna and the Spirits behind her feel uneasy.

Countless metallic tentacles emerged, moving forward and distorting space around them, warping it. Anna instantly felt her Domain beginning to shake before this presence.

A giant crimson eye could be seen within the King of Steel’s opened chest, made of red glass and glowing with artificial light.

It was all artificial, yet why…

Why did it feel so strange?

So bizarre?

So disgusting?

[A Mechanical Spawn of the {Universal Computer} has been Awakened from its Slumber…]

[Its Crimson Eye glares at the world as its mechanical tentacles begin to pierce through space, trying to find materials it can absorb.]

“He has a spawn of a Void Ruler inside of him?!” Anna lost her cool for a moment; it wasn’t something she could take calmly at all.

“T-This is the power she gifted to me!”

The King of Steel laughed.

“To become one with her Machine Empire, to become one with her… I had to accept her offspring within my wires and circuits!”

“T-That’s disgusting…!”

“King of Steel, why?!”

“He has completely lost it!”

“He’s… no longer our friend, indeed.”

“So he did everything for power, huh?”

The Rainbow Knights behind Anna were slowly growing weaker, their colors becoming fainter; it seemed they couldn’t be here for too long.

Anna had to finish this before it escalated to an even more ridiculous level!

“We’ll end this right here and right now. I’ve had enough.”

Her eyes glowed with golden light, cosmic energy flowing through her armor and body.

And then, two other energies emerged.

Darkness and Shadows, concentrating within her body and soul.

Crimson Light and Blood, fusing with her flesh and bones.

These two energies came from the equipment that composed her armor.

Abyssal Essence from the [Abyssal Demonic Phantom Eye Gauntlet].

And Blood Essence from the [Mad Blood Rose Princess’ Armor].

Both pieces of equipment were made using tiny fragments of the Essence of two different Void Rulers.

One was a gift to her.

And the other? She took it from them.

“To fight an abomination, I will use another abomination’s power.”

The energies within her armor gathered, fusing together.

The tentacles were already about to touch her, to devour her mechanical armor and drain her of her energies!

“[Maddening Scream]!”

“GYAAAAAAAHHHH!”

A scream that reverberated through planets and universes echoed, the scream of the manifestation of countless universes suffering into a single entity.

The Bleeding Scream.

“Nnnggh?!”

“Gryyaaarrgh!”

Both the King of Steel and the Spawn screamed in agony; the shockwave, amplified by the mechanical armor, was several times stronger than before!

TRUUUM!

It was so strong it shook the very spawn of another Void Ruler, its tentacles trembling, and suddenly beginning to explode.

BOOM! BOOM! BOOM! BOOM!

The new upgraded [Maddening Scream] could deal much more damage than before!

“Amazing!”

Anna smiled but didn’t let that slight advantage get to her head.

She had to hurry up!

FLASH!

She kicked the air, rushing forward with all her might, resembling a golden star amidst the cosmos of her domain.

“D-Don’t think you’ll get away with that alone!”

The King of Steel regained consciousness faster, as he quickly summoned the rest of the Aurora Weapons, an Axe, a Hammer, and a Bow.

“{Aurora Axe}! {Aurora Hammer}! {Aurora Bow}!”

The Axe and the Hammer were grabbed by the long tentacles, which he could also control as the Spawn had merged with him.

They rushed down towards her as she flew through the cosmic domain’s stars, enormous weapons that could cleave through entire cities!

CLAAASH! CLAAASH!

Using the shield she had already summoned, she resisted two enormous blows while releasing a beam of light from her legs, managing to not get pushed down.

And then, she summoned the Katana again…

Did you know this story is from Royal Road? Read the official version for free and support the author.

And also another weapon, a long spear—no, a polearm.

“{Mighty Morphin Weapon Manifestation}: {Golden Nine-Tailed Shadow Fox’s Polearm}!”

FLUOSH!

Darkness and golden light converged into the majestic weapon as Anna pierced through both of the Aurora weapons by swinging the weapons forward, massive cosmic energy concentrations manifesting gigantic shockwaves, piercing through the cosmic metal.

CRAAASH!

“T-The weapons shattered again so easily!”

The King of Steel despaired; more tentacles rushed towards Anna from every angle. The Void Spawn was rapidly beginning to regain its consciousness, its attacks becoming more precise and faster.

And yet…

“[Void Veil]”

FLASH!

Anna suddenly disappeared.

“Wha…?!”

“?!”

Both the King of Steel and his parasite were unable to detect her, see her, or even feel her presence at all!

Despite her being right there, she was completely gone.

The Spawn was unable to track her, even as it moved its tentacle everywhere.

She had become veiled by the void, unable to be seen or heard, or even sensed, no matter what.

It lasted for only a few moments, but it gave Anna the chance she needed.

She reached the legs of the King of Steel.

With her two weapons, she cleaved through both legs made out of the Black Tortoise Machine.

It was one of the toughest parts of the King of Steel at that!

CRAAASH!

RUMBLE!

A shockwave was unleashed; the Void Veil immediately came undone upon her attacking someone. The King of Steel and the Spawn noticed her all the way down there, instantly rushing to kill her with their tentacles.

“DIE!”

The King of Steel screamed furiously, the Spawn within him making him even madder than before as it awakened from its slumber.

“Come on….! Harder, push… HARDER!”

Anna roared; her mechanical armor’s blessings manifested as four golden beasts, encompassing her body and turning her armor into muscle fiber-like material.

Her physical prowess skyrocketed at that moment, as the fading away Rainbow Knights gathered behind her, summoning their spiritual weapons and fighting the tentacles!

“We must defend her! At all costs!”

CLASH!

“Even if we fade away, it doesn’t matter!”

CLASH!

“Anna will do it!”

CLASH!

“I trust her!”

CLASH!

“You can do it, Anna!”

CLASH!

As she heard them fighting and rapidly beginning to fade away faster, Anna gritted her teeth, activating the Raijin Skill, as electricity flowed through her armor, erupting with immense power.

RUMBLE!

Her hair became like golden electricity itself, wrapping around her entire body as she pushed with all her might.

And then…!

Crack, crack…!

CRAAASH!

Both of the gigantic legs shattered into pieces, exploding right afterwards, dealing massive damage to the King of Steel’s remaining torso.

BOOOMMM!!!

“UUUAAAGGH!”

The explosion engulfed the tentacles, disintegrating dozens of them and weakening the Spawn as well, who seemed to give out a loud, metallic groan.

“GRYYYAAAGH!”

As the two suffered tremendous damage, the Rainbow Knights, or whatever was left of them, converged into a ray of cosmic rainbow light.

FLUOSH!

“Anna! Now!”

“While the King of Steel is weakened!”

“You must end this, please!”

“This nightmare… it has to end now!”

“We beg you!”

“I know…” Anna nodded. “There’s no need to beg me; I’ll do it.”

Anna became a star made of many colors, piercing through the King of Steel’s body in countless pieces, zigzagging through his metallic torso, head, and tentacles.

Both of her weapons were at the front, cleaving through all metal!

CLASH! CLASH! CLASH! CLASH!

As this happened, the King of Steel barely regained consciousness; his body was already in shambles, torn to pieces!

“N-No…! Wait…! Urk…! You damn useless spawn…! D-Do… Do something!”

“Gryyeeeck!”

However, he heard the Spawn screaming in agony as Anna rushed through its eye, blowing it up and then destroying the core of the mechanical being.

BOOOM!

Making it explode into pieces.

“This is not the first time I’ve fought the spawns of Void Rulers!”

Anna recalled the time she went to one of the many Hells, fighting the Vampires terrorizing the last surviving Demons, and how they had all become the vessels of parasitic spawns of the Bleeding Scream.

“S-She killed it?!”

The King of Steel faced the shadow of death; it was rapidly creeping over him, encompassing him completely.

His very being was beginning to become undone, as he was dying.

And Anna, rushing in front of him, carried with her the souls of those he slaughtered.

The ones that believed were his friends, but that ended up being betrayed by his greed and selfishness.

“After everything I’ve done…! T-This is how… I die?”

Anna gathered all her armor into a single point, as her body was unguarded.

Her armor transformed into a massive weapon.

A gigantic sword with a golden handle and a rainbow blade.

With the power of the Rainbow Knights, she unleashed the real Aurora Blade.

“Now, team! Together! Courage!”

“Yeah! Hope!”

“Friendship!”

“Love!”

“Miracles!”

Their colors merged into a single, beautiful weapon!

And their voices converged together.

One last time.

“{Mighty Rainbow Aurora Blade}!”

SLAAASH!

Its divine, cosmic light sliced through the Constellation, and everything it encompassed of everything it was in the past, what it is now, and even what it would become in the future.

Its Story was shattered into countless pieces.

“UUUUUAAAAGGHHH!”

He couldn’t help but scream in agony, perhaps as his last effort to resist death.

Although it never regretted anything it ever did.

The rainbow light encompassed him entirely until he finally stopped living.

BOOOMMM!!!

Everything that made him end up exploding as Anna’s Domain came undone in that moment.

Anna glanced into the skies, feeling slightly tired.

A rain of rainbow light fell over her body, feeding her with great strength.

The King of Steel’s Cosmic Powers were rapidly becoming hers.

Uroboros, and now him.

Two Constellations have been devoured now.

She felt immense power coursing through her entire being, her hands overflowing with cosmic energy.

All the energy she lost in that battle was regained, with a plus.

She gained new Traits, and her Dao Root expanded; its phantasmal form became more real, solidifying within her Soul.

And she saw images; she saw the Story she absorbed.

The story of Five Mechanical Beasts, and Five Chosen Heroes.

Their battles, their hardships, their victories, and their defeats.

And how, despite everything, they always stayed together until the bitter end.

The tale of the King of Steel continued upon their death, conquering planets and destroying worlds.

Completely unhinged, a monster.

Until she showed up and made his Story end in that very moment.

The heroes that he had slain reappeared one last time to end this nightmare once and for all.

“Thank you, Anna.”

“Huh?”

She saw behind her their silhouettes made of colorful lights, fading away below the sunlight.

“That was fantastic…”

“You are indeed one of us now, aren’t you?”

“That’s right! She is!”

“Thank you for freeing us from this nightmare.”

“You guys…” Anna shed another tear. “Are you going away now? Can’t you stay? I could—”

“Our time has come.”

“We cannot… remain any longer.”

“Our souls were tied to the King of Steel’s Story.”

“With his death, so we will fade away as well.”

“No! Wait! I could fix this…!” Anna tried to convince them, but…

“It’s enough…”

“I want… to rest.”

“We were forced to see everything he did.”

“We’ve been tormented so much…”

“Honestly, we need a retirement right now.”

“I… see…” Anna gripped her fists tightly; in the end, she couldn’t do anything. “I wonder if there is another Worldline where you survived? Another world where people like you are still fighting against evil?”

“Perhaps…”

“But honestly, aren’t you like us?”

“Yes, that’s right.”

“You are one of us, our sixth member now.”

“S-Sixth member?” Anna gasped. “Really?!”

They laughed a bit.

“Hahaha, you’re too excited!”

“Of course!”

“You’re the Golden Knight, Anna.”

“We leave our legacy with you.”

“Please, take care of this power.”

“The Morphin Core cannot be misused. We trust your judgment.”

Anna saw a crystal sphere of rainbow colors floating towards her. She hurriedly grabbed it, shocked by its powerful aura.

“Thanks… I will make sure to protect it. Your legacy!”

They nodded; their bodies were almost already gone.

“Then… team, it’s finally time.”

“Let’s go…”

“Wherever we go, let’s go together.”

“Yeah, we’re family pretty much, aren’t we? Heh!”

“Laughing until the last moment, huh? You never change…”

“It was brief but… Thank you! I’m really happy to have met you!” Anna cried as they disappeared one after another.

The Red Knight looked at her one last time as he disappeared.

“And we were lucky to have met you too, Anna. Take care. You have a world to save.”

“Yes, sir!”

Anna nodded as the Red Knight disappeared.

She looked into the distance, at the Mechanical Tree.

“I have a world to save…”

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