The Protagonist’s Sister Is Actually The Strongest [An Action-Packed LitRPG Transmigration and Progression Fantasy]

Listen while reading: Berserk - Behelit

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The memories flowed rapidly, like a stream of countless images, and Beelzebub felt completely absorbed by them. They carried so much emotion and so much strength that it was overwhelming. He couldn’t fight against them.

He was trapped, constantly watching them and reliving these moments. He tried to escape, but he could not; invisible chains restrained his actions.

“T-This bastard…! Who is he?! How can he- ARGH!”

Another stream of memories rushed towards him, and as Beelzebub’s consciousness slowly ground through countless Memory Bubbles, the will of Heisenberg was beginning to absorb his own mind.

“Stay with me; I want you to watch more, Beelzebub.”

His voice echoed inside the demon’s voice, making Beelzebub feel a chill through the rest of his soul. This human wasn’t normal; he was completely different than any other human he had dominated and enslaved before.

FLASH!

He was quickly absorbed into another memory, showing Heisenberg and the children being jailed inside completely white rooms. One after another, they were dragged out; many of them never came back, while those that did came back different. They roared like beasts, vomited blood, and their eyes constantly changed colors.

“Stop! Don’t you dare! STOP! AAARGH!”

Eventually, it was his turn. They dragged him away against his will, restrained his movements, and didn’t even apply anesthesia because it would be a waste of money, according to them. He could still vividly recall the smile of the scientist who brought him there.

“Now, now, I’ve been looking forward to experimenting on you, young lad.” He laughed. “Unlike the rest, you are awakened, aren’t you? You’re a very weak one, but that Aura of yours... I can’t wait to see what you will become. What you will blossom as!”

“Y-You damn old bastard... One day, I’m going to fucking take your eyes out with my bare fingers! I’m going to bite off your nose, and I’ll tear your neck to shreds, and I will enjoy it. I WILL FUCKING ENJOY IT! I WILL-”

“Yeah, yeah, say whatever you want. The more they resist, the more entertaining it is.” The professor laughed.

“Professor Newtown, shall we begin?” Another person in a white lab coat asked him.

“Yes, begin immediately.” The old man nodded.

At that moment, the mechanical sound of large machines moving around Heisenberg echoed across the large hall. The young lad’s eyes glanced in utter horror as the machines pointed countless needles filled with different and colorful liquids, containing the DNA of many monsters.

“Let’s try them all on this little bastard. If he’s awakened, he can resist it, right? He has strong tenacity after all.”

“Y-YOU- AARRGH!”

Heisenberg was unable to muster another world as dozens of needles pierced his body, injecting into his body all sorts of bizarre cold liquids. His entire body convulsed, and he started bleeding from all his orifices as he began to feel a horrendous burning pain coming from the depths of his chest.

His heart was beating faster and faster; he felt like, at any time, it would explode out of his chest. The pain continued spreading to every fiber of his body; his muscles distorted and tore apart before reconstructing again; all his bones started shattering; and the pain made him pass away only to wake up due to it.

“AAAAAAGGGHHH!”

The same agony he went through was shared with Beelzebub; the demon’s will slowly faded away as his soul seemed to be slowly beginning to be infected. The agony was the only thing he knew now.

“Do you feel it too? My pain.”

“S-STOP IT…! STOP THIS!”

“I can’t… These are just my memories. It is what makes me who I am, Beelzebub.”

“You’re nothing but a human! Do you think your stupid traumas can make you stronger than me?! That your will can surpass mine?! That’s ridiculous—UGH?!”

However, before he could say another word, Beelzebub’s mind was dragged to several more dreams, showing the years and years of agony Heisenberg went through, the sorrow of seeing many friends die, and the endless, accumulating anger towards his kidnappers.

The once pristine labs changed their appearance, now drenched in blood, and dozens of corpses spread across the floor. Flames were constantly burning the equipment, while the same young boy who was once treated like garbage was now several times taller, more mature, and with eyes full of resentment.

“How did you even break through the restraining mechanisms?! How did you? That shouldn’t be possible! We even put Stigmas of Obedience on your bodies!”

The old man, Professor Newtown, the bastard that tortured Heisenberg and his friends for three long years, was now cowering at the end of a corridor. The last survivors, the strongest of his creations, all stood over the corpses of his many assistants, their eyes staring into his very soul.

“It’s all your fault, Newtown,” Heisenberg said. “It was as easy as absorbing the runic engraving and rearranging it before leaving it be. I did it with everyone; we pretended to be your pets for a week, preparing to strike. It is thanks to you that we gained this power. And with it, we will reshape this entire world as we please.”

“N-No! Stop! You’re not supposed to be free! You’re bioweapons made for the government! You will bring our country back to the heights it once achieved before the Awakening! We will once again become a superpower, a whole nation with super soldiers, powered by the chimeric genes I’ve perfected on you!” Newtown cried. “You have to understand! You can’t leave! You’re my magnum opus! I can’t… I-”

CRASH!

His words were interrupted by the searing pain of Heisenberg’s hand piercing his chest and grasping his still-beating heart. A wicked smile surged on the young man’s lips.

“N-No… S-Stop…”

“I was going to torture you first... But I’ve changed plans. I have no time to waste with trash like you.”

Heisenberg’s crimson eyes stared at Newtown’s brown eyes, slowly beginning to tighten the grip of his hand, crushing the old man’s heart until it exploded, blood splattering everywhere.

SPLAT!

“Graarghh…!”

The doctor dropped dead on the floor after giving out one last whimper. His death signifies a new beginning for him and his siblings. Heisenberg smiled, never having felt this much satisfaction before. 

“We’ve perseverated this entire time, but now it is finally our turn.” He smiled. “We will take back everything that was taken away from us. Our freedom, our happiness, and our time. We will now redefine this world. We will change it. I am tired of it. I am tired of everything. I only need you with me—nobody else. A world where the strong rule over the weak. This is the world I envision. We will destroy society as a whole, and we will let the monsters thrive instead. This world shall be submerged in endless bloodshed. And we will watch as they struggle, fight, cry, and scream, just like we once did.”

Heisenberg then glanced back at his siblings; his eyes filled with insanity.

“Will you follow me?”

Without hesitating, all of them nodded; they were his siblings, his family. With them by his side, he felt invincible. He felt like he didn’t need anything or anybody else. They walked out of the labs as the entire building collapsed, and before the police could arrive, they were already gone.

“You’re nothing but a steppingstone to my ultimate goal, Beelzebub.” Heisenberg’s voice echoed. “My siblings have sacrificed themselves for me; I’ve lost many, so many of them... All to achieve this goal. And I will not disappoint them. I will destroy this world and create a new one. This is the Dawn of a New World.”

“N-No… This is impossible! What… What truly are you?! YOU’RE JUST A MERE HUMAN! A SIMPLE CHIMERA…!”

Beelzebub was quickly swarmed by countless black tentacles, piercing his body and tearing apart his entire soul. Countless crimson eyes stared into the depths of his soul, his emotions swirling until he felt utter fear! He struggled, he fought, but ultimately, he was assimilated.

“HEISENBERG! Even if you assimilate me,! I will not die! I will remain within you. And I will WAIT, no matter how long... To take back what’s mine!”

“Thank you, Beelzebub. Without you, I would have never been able to grow this far. I owe you so much. Of course, you can remain within me. I will always remember you.”

Beelzebub was completely assimilated, as Heisenberg’s cocoon, floating above the skies, quickly became solidified, floating in midair. Darkness and crimson lightning gathered around it. The demonic beasts and even the monsters outside of the city walls all directed their gazes into the skies.

Something within their instincts was telling them that their King was about to be born. The darkness of the skies, the demonic crimson lightning—it all swirled around the black cocoon within seconds, as if feeding the fetus that was growing inside.

Heisenberg found himself drowning in an endless sea of darkness and memories until he finally found himself elsewhere.

A boundless horizon of stars and darkness, with no end in sight. He watched with wonder until he saw something emerging from within the void.

A titanic figure, a behemoth that expanded across countless light years, boundless and unshackled, a Void Ruler. Their endless eyes glanced into his very soul.

“You have stolen the Soul and Powers of someone who was once an Archdemon.” Hundreds of different voices spoke at the same time inside Heisenberg’s head. “You have accomplished something unprecedented. Tell me, child of man. What is your wish?”

Heisenberg’s crimson eyes faced the calamitous being without fear; they were full of both wonder and desire. The desire for something he had always wanted, since he was a child in the slums, since he fought for his life since he starved, and since he was experimented on.

He used to always watch the skies and the birds flying across the boundless blue heaven. There was a wish, something he often wished for, but that he always knew was stupid and that it would never become a reality. His gaze changed, full of arrogance. 

“I want wings.”

The countless eyes of the Void Ruler widened and then squinted. Hundreds of different voices spoke at the same time inside his mind.

“What a peculiar wish.”

Darkness engulfed Heisenberg once more, and his whole soul metamorphosed. It was painful, but wings grew out of his back. These were not just physical wings; they were the wings of the soul, to be free and unshackled.

His soul darkened and gained crimson hues; it changed, and it evolved—demonic powers swirling from within, like an endless spiraling black hole of power.

“There it is... This power…”

The demonic beasts summoned by Beelzebub and the monsters outside all whispered to one another, as if they knew what was happening.

“The birth of a new Demon King…”

“It is soon to come!”

“We must greet him with a feast of blood and flesh!”

“Oh, Demon King!”

Demon Kings have a completely different existence than the Death Apostles. While Death Apostles were Calamities that constantly attempted to ascend into Archdemons and roamed worlds to harness such power, Demon Kings were different; they were beings between Mortals and Constellations, that had no desire to ascend but to remain where they were.

“It feels like I am finally becoming what I was always destined to be.”

They were guardians of the breach between the Mortal Plane and the Cosmic Plane, ruthless tyrants that slaughtered and brought despair and destruction, but that were neither organized nor predictable like the cunning and scheming Death Apostles. It could be said that they were more like forces of nature than anything else, the embodiments of an entire World’s Sins. 

There was only five Demon Kings; two were missing. And Heisenberg was pupating into the sixth. Demonic beasts and monsters alike, deep within their instincts, knew that they had to obey the Demon Kings, no matter what. 

“I will finally accomplish my goal, my siblings. I will destroy the world. And then I shall make a new one from its fragments, all for you.”

As Heisenberg’s transformation was slowly coming to an end, a sudden blast of lightning and cosmic power stopped it all. The darkness slowly helping him awaken twisted and disappeared; the fetus he had become was left incomplete.

CRASH!

“Huh?!”

The cold and searing pain of two swords piercing Heisenberg’s chest woke him up; his demonic, crimson eyes and his half-transformed body within the cocoon quickly started to twist in agony.

“No matter how harsh your life was, it doesn’t justify genocide, Heisenberg.”

Anna’s voice awakened Heisenberg from his dream; the cold air over his incomplete body made him agonize the most. The swords piercing his chest and destroying his demonic heart made him vomit blood. And amidst the pain and agony, there was still something that was growing stronger.

His rage!

All of his dreams, all of his hard work, and all of his efforts to get this far were all shattered in front of him by the selfishness of someone who wanted to protect this world. This damned, horrendous world?!

It was unacceptable. 

“Y-You… How dare you interrupt me from the greatest moment of my entire life?”

As Anna saw Heisenberg’s eyes crying blood, she quickly noticed countless demonic stigmas growing all over his incomplete body. The man opened his mouth and started to scream.

“Shit…!”

“RAAAAGGGHH!”

A scream of agony, rage, frustration, and pure madness generated a tremendous shockwave. Anna was blasted away in a single second as Heisenberg’s incomplete body continuously tried to remain stable.

“H-How dare… you… I will bring the world’s destruction, NO MATTER WHAT!”

The half-demon king screamed to the skies, all his power concentrated into a single spot, until the dimensions broke and opened, leading to a world of flames and bloodshed. Thousands of demonic entities started looming from the portal’s horizon.

[You have successfully stopped the birth of the {Sixth Demon King, The Selfish Chimera}!]

[However, the incomplete Demon King has activated their Privilege: [Demonic Hell Gate (SS Rank Privilege)], bringing forth an army of Demons from the 434th Hell!]

“Big brother…” Annabelle tearfully glanced into the skies. “Is this what you truly wanted to become?” 

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