The Protagonist's Sister Is Actually The Strongest

RUMBLE!

The underground caverns trembled. A battle between my entire party and the robots below was going on full swing. The explosion of demonic flames, holy light, and laser beams reverberated across the wide underground corridors. A never-ending swarm of hundreds of mechanical beasts rushed towards us.

This time I didn’t ask the Death Apostles to become weapons or equipment; although I had considered that for my Familiars, who were slightly weaker before being able to evolve again, I reconsidered that and decided to summon them as bodyguards instead.

Now that their souls are bound into the Purgatory, even if they perish now, they’ll respawn inside the Purgatory and take some cooldown before fully regenerating and being able to be summoned again.

This played around with the concept of Death Apostles being entities that could create manifestations of themselves. Their “true bodies” were their powerful Demonic Souls, which were kept sealed shut inside the Purgatory.

This made it so I had a squad of suicidal death apostles ready to roll with anything I had in mind anyway, in exchange for better treatment and food later. Some even asked me for specific things. Neberius said that as long as I give him some delicious seeds later, he’ll be fine.

Meanwhile, Astaroth asked for grilled meat from the highest-quality demonic beasts I could find. I think I had some in my inventory, so I’ll be feeding him that. All of them had specific conditions like these.

Although I could force them to cooperate anyway, it wasn’t my style, and I wanted a relationship with them that felt more like equals than a master and their slave. I don’t want to take any slaves.

They already knew they were “forced” into this situation due to their misdeeds. I could have easily killed them like I did with Uroboros, but I decided to keep them alive instead. They’ll pay for their wrongdoings by helping me do good things instead.

Isn’t that a nice sentence?

CLAAASH!

My Nameless Axe-Sword clashed against the head of a giant spider-like mechanical beast. I didn’t even activate its special abilities as they consumed a lot of Mana, which I didn’t have, and it would consume too much Ki.

However, the weight alone of this weapon was more than enough to pulverize the heads and limbs of most of the generic mechanical beasts. Although the three basic techniques require Mana, the Labors consume no energy but are limited to a certain amount per day, so I am saving them when I fight a big enough foe.

“SHAAAH!”

“GROOOH!”

“ROOAAR!”

Over a dozen more mechanical beasts rushed from behind me, opening their jaws and pointing their sharp metallic fangs and claws against me. Tigers, wolves, spiders, ants, and mantis-shaped ones were the most common of them.

The ants were mostly designed as workers that carried items; the mantises used their pickaxe-shaped arms to dig the ores; and the spiders opened the caves by digging them and securing them with spider-web-like substances. Tigers and wolves were guards and were not as numerous.

They were all fiercely fighting, but it was clear that the miners and carriers were simply not made to fight against the Martial Artists of a Murim World.

And it showed.

CLAAASH!

Their claws and fangs reached me, yet I was able to block them with my weapons, Gram and the Nameless Axe-Sword, and my own armor and body. The combination of several passive skills boosted my endurance and weight, with the best ones being Warrior Princess Physique and Steel Body, my tough armor, my shield, and my weapons and martial arts.

I was kind of invincible right now, and for once, it felt really good.

“What? Is that all you’ve got? You’ve tormented this world’s people and killed almost everyone, but you can’t stop a single girl from coming to destroy your little factory?”

“RAAAH!”

The robots were clearly pissed, with the tigers opening their jaws to unleash beams of neon blue laser energy. Which I quickly sliced with Gram, releasing a wave of bright golden celestial ki.

“{Sunlit Arc}”

SLAAASH!

I spun in midair at the same time, stepping into the air and then ravaging the mechanical beasts into smithereens; whatever touched my weapons ended up either being crushed or slashed apart.

I stepped forward, each step releasing shockwaves of golden, draconic Ki, as I called it, which was the combination of the Golden Dragon Martial Arts power alongside my Celestial energy.

Each step made the ground tremble, and each attack devastated a dozen more machines, yet they keep coming and coming and coming, endlessly!

“You guys are way too many! I can’t believe that Heavenly Demon let you multiply so easily; for being so mean, he sure is a lazy bastard.” Sepa complained that she was currently possessing Violet’s body, making the giant demonic insect gain a golden exoskeleton and a cosmic aura coming from his body.

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“KRIEEEH!”

SLASH!

CRAASH!

My loyal Familiar slashed apart the mechs with his giant scythes as he constantly grew in size to gain more bonus stats. He was also gaining more stats thanks to Sepa helping him. They’ve been practicing this fusion for a while now, and both have become quite accustomed to it.

Violet was an amazingly fitting vessel for Sepa, and Sepa was becoming more used to transferring a part of her Cosmic Soul and Consciousness towards him. This fusion could usually last five minutes at most, but they were now able to keep it up for over twenty minutes.

This is the power of endless practice!

And of course, my own Cosmic Energy growing in quantity, allowing Sepa to do many more things.

“Awoooo!”

Although Snow was more of a Baihe’s mount than my own Familiar, Baihe wasn’t here to further boost his stats by being near him, so he had to fight on his own. Without Mana, it was a bit difficult at first, but he was getting a hang of his internal Ki very quickly, especially because he had always had a physique from the beginning since we adopted him back in that dungeon.

FLUOSH!

His might howl released waves of frost, freezing over thirty robots from advancing any further; this wasn’t a spell but his own Frost Ki Aura Release Technique, a Martial Arts this puppy had developed on his own! I am sure his mother would be proud.

Once over thirty robots were frozen, a giant golden cat appeared above them, leaping towards them and then descending like a blazing meteor, encompassed in pure golden light.

BAAAM!

The Primordial Martial Beast of Radiant Yang released a wave of purifying Primordial Ki of the Light Spectrum, encompassing Light, Thunder, Life, Fire, Nature, and many other elements at once. The shockwave was powerful enough to quickly shatter the frozen robots into pieces.

“Mereow!”

The adorable, gigantic kitty gave a loud meow. Although I couldn’t tame him, he was obeying my every order, and he had become an incredibly useful ally to have. Not only was it able to purify anything it touched, but its natural aura enhanced the regeneration of health points and ki when being near it! And well, it was extremely strong. It had already taken several hits without showing a single scratch on its body.

I never thought that from all things these quests would reward me; giving me an overpowered pet was on the last of my list. It is ideal when fighting so many foes at once! The Death Apostles were also all fighting and joining the fray, protecting Snow and Shiro and taking damage while fighting themselves.

Their attacking methods were all overwhelming, and each one had their own techniques and abilities. Although their souls were sealed, the higher the level of the Purgatory Skill, the more powers they could unseal. Right now, they have roughly 30% of their total power, stats, and abilities.

And when I say total, I mean completely and total amount, based on their Demonic Souls themselves, not their Manifestations which usually were between 10% and 20% of their total Power, and the reason why they often had to rely on fusing their Souls into a single Manifestation like it happened with Astaroth, Aim, and Neberius, or when Astaroth relied on becoming the temporary incarnation of three Evil Constellations at once.

Explosions of demonic flames, black feather projectiles, slashes of blades, piercing blows from spears, lightning strikes zapping everything out—the Death Apostles didn’t hold back at all, and the robots were being cleaned nicely as we advanced.

In the distance, I could see it; there was a huge factory attached to several roots and enormous metallic tubes. It was closely shut and further protected with a neon blue barrier. However, surrounding the factory were at least two thousand more robots, and the factory kept producing them, opening its gates to release dozens at a time.

The robots continued charging; every time I took down a few dozen, even more took their place, surrounding me. Even with all the allies I had, my equipment, and my abilities, this was a very tough spot to be. I was getting there, but way too slowly. And I didn’t have that much time to get this done.

“Time to experiment then.” I smiled.

“{Rise}!”

I felt a large quantity of my Ki leaving my body, at least eighty percent of my total reserves, which forced me to recover it by drinking a Ki Elixir right afterwards.

And as that happened, waves of Ki became tendrils, connecting to hundreds of robot ”carcasses.” My necromancy Abilities allowed me to raise any “carcass” into an Undead, and this time, I decided to use the robots against themselves.

There were at least five hundred robot carcasses nearby, and with all the Ki I used, which ended up emptying my reserves again as I drank a second Elixir, the Holy Herculean Undead Mechanical Beasts rose.

“OOOHH!”

“GROOH!”

“RAAAH!”

With guttural and metallic groans of anger and beastly anger, the Holy Undead rose. Their entire bodies are changing. Although they remained looking like walking scrap, their bodies were encompassed by armors of light, a shiny halo on top of their heads, and powerful muscles.

Yes, muscles!

Their mechanical bodies and arms swelled through the powers of my Specialization, giving these mechanical Undead both the properties of Holy and Death Element at once.

Ding!

[You have used your {Main Specialization}: [Legendary Herculean Holy Necromancer (S)] and the related Skills to raise [Legendary Herculean Holy Undead Mechanical Beasts (S Rank)] x507!]

[The [Ruler of the Dead (S): Lv4] Skill Effects have been triggered; all risen Undead Stats and Reanimation Duration have increased by +200%]

[The [Thanatos’ Stigma (S): Lv2] Skill Effects have been triggered, All Undead Summoned gain the following Effects: All Stats +70%, Reduces Damage Taken by -35%, Increases Damage Dealt by +55%, grants Any Physical Attack a 50% Chance to inflict [Paralysis], [Necrosis], or [Poison] on an affected Foe, the ability to use one selected Skill from their Master (must match the Undead’s powers), all Summoned, Risen, or Fabricated Undead will always be loyal.]

[Your {Main Specialization}: [Legendary Herculean Holy Necromancer (S)] Effects have been triggered, and all Summoned Legendary Herculean Holy Undead receive the following Effects: Reduces Damage Taken to the Body by 15%, Increases Mastery over All Weapons by 50%, Increases Damage Dealt using Physical Force by 10%, Health Restoration Speed increases by 25%, Musculature Development Speed increases by 100%, Increases Holy Light and Death Magic Power 25%, Decreases Holy Light and Death Magic Mana Consumption by 25%, You can conjure Spells using Ki, but at twice the price.]

[Summon Duration: 3 Hours.]

The effects kept stacking; it was completely insane. The Undead ended up becoming at least three times as strong as they already were, and with all those effects stacking on them, they seemed even stronger than when they were alive.

“Advance! Open the way!”

As I roared, the Undead moved forward, conjuring swords made of light and death essence and even giant shields made of the same elements, both tanking hits and dealing constant physical and magical damage.

As we got closer to the factory and whatever was controlling it realized its attempts at summoning more robots were only fueling my summoning abilities, something else was created.

It stopped producing smaller robots, and a slightly different entity emerged.

It was three meters tall, made completely out of obsidian metal material, decorated with three red jewels on its head; its arms and legs were pointy, like needles; and it had no head.

It emanated a strange, yet corrupted Aura of Electromagnetic Energies and Ki…

[The [Mechanical Factory] has summoned its ace! The [Black Heaven Android Prototype (SS+ Rank)]!]

Black Heaven?!

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