Previous Era

The crafting of MANTIS was no easy task as people view it, it is not emerging as a Honkai fighter, but rather becoming another existence, not considered human anymore. It was the pinnacle of genetic engineering, the knowledge that was able to turn the tide against the Herrschers.

Each and every MANTIS were created with the genes of a powerful Honkai beast, granting them incredible resilience, regenerative and power compared to the other humans, they were mainly used as a tool to kill Honkai creatures and are a desperate tool to slay the Herrschers.

The MANTIS all have their unique abilities corresponding to the beasts they fused with, some stood out more in the bunch.

Such as Ben Dover's, only known as the Howling.

And John Y/n's, "The Moving Castle".

"It was a difficult battle as I can remember it, back then the amount of MANTIS that could be deployed was around 20, yet all of them were mobilized to fight this thing."

"It was that difficult?"

"Yes, but it by itself was not enough of a lethal opponent, the MOTH deployed everything they could to weaken and stall it, yet it braced and walked past them like nothing, an immovable object set on a fixed path, nothing could stop it."

"Not even you guys?"

"Come on, we are called the best fighters against Honkai, and yeah we couldn't, things were too tough for us to crack."

"..."

"Even Kevin himself actually struggled to take it down."

"You mean Kevin???"

"Yeah, the thing was no joke... In the end, everyone had to be evacuated for Kevin to nuke it, he even rated it as the toughest target he had ever seen before... I bet Kalpas would love using it as a punching bag."

"Kevin our goat."

"Due to its incredible resilience and fearsome abilities after engaging it for hours... The higher-ups have named it The Moving Castle.. hope it won't get copyrighted. And I wish things would not go down in such a way that he would have to release that power..."

And now, the full might of John Y/n, a MANTIS is fully released.

"Active Reaction Honkai form... The Moving Castle."

It has begun, the transformation, the ultimate form of a true MANTIS, one that would only be used in the direst of circumstances. John Y/n can feel every cell on his body just got oiled up, they are getting funny as he is thinking to himself how to cook that pig after this.

Adaptation... The ability allows the user to adapt to any kind of attack or environment around them quick enough so that it would be useless against them the next time it is used. By itself, the ability was already scary enough when its always on passive, but now, with the Active Reaction Honkai form, it is going to be triggered constantly for every single cell in his body, each adaptation cycle will overcome the last, in other words, Y/n's power if given enough time...

The pig squealed as it was punched in the face, and took a blow heavy enough that it stepped back in fear, but then quickly replaced it with anger.

...he is capable of taking the Higher Existence before him down.

"Ah... Damn it, I can feel like my entire body is on fire... It got extinguished just to get lit up hotter next time, nah forget it, because you will be in something hotter later piggy."

The pig now gets a clearer look at the mortal who is now capable of taking him down, a force to be reckoned with, and since the author really suck at describing appearances, I would leave it to your imagination when I say it is your coolest form ever.

You leapt forward, another attack was about to be landed on the pig but he learned too. He knew that his size alone would be enough to guarantee a hit no matter what, so he threw himself back slightly before accelerating forward rapidly. Although he managed to hit you, he still received a hurtful blow from him.

The Adaptation alone, even at this level wasn't enough to completely adapt to the attack to one of Higher Existences. As such, your body still receives injuries... But you felt your body become more reinforced than ever... Every cell in your body is fighting themselves to become a better version of themselves.

"Bring it on you damn pig!"

More, more, and more punches around. The fight was cruel and devastating to the surroundings of the Sea, the corpses of old branches fell from the Imaginary Tree were being wrecked left and right, the vast Sea, home to countless creatures that could easily chew be compared to Emperor-Class Honkai beasts is now a battleground for these two.

The longer the fight lasts, more injuries appear all around your body as the pig does not hold back at all, but at the same time, you simply just gain more power, your power has now reached the peak of the peak.

The pig suddenly opened its mouth, trapping you inside, which was a surprise to you. And then it tried to chew you too, but since you were too small, Adaptation alone was overkill as you slid easily between the crack of its teeth.

"AHHH!!! Ahhhh!!! Ahhh..."

The pig suddenly felt something was wrong when you stopped screaming, then it felt a sharp pain in its mouth, one of its teeth was literally getting attacked.

"I GET IT NOW, I UNDERSTAND IT NOW!!!"

Out of horror, it licked the attacked teeth all around before spitting you out of its mouth, before giving you a chance to react, he stomped on you aggressively and many times in a row too, destroying a lot of stuff in the process.

When it finally stopped... It took a few steps back to look if you are dead or not, only to see you slowly getting up to your knees, bleeding all over yet it seems like these injuries did not bother you at all, some of them have begun to close.

The pig, as a Higher Existence without knowing itself as one, only knows one thing : You will stop at nothing to kill it, so as it sees that you won't go down... It simply turned around and tried to run away.

"Nuh uh! Get your pork chop ass back here boi!"

You screamed as you immediately chased after the pig through different layers of the Sea. Never have the Sea and the Tree see a Higher Existence fleeing away from a mortal, well, not exactly a mortal but you get the point.

The pig does get a few more punches here and there, this shouldn't be possible at all, how can a Higher Existence such as it be harmed? Yet the situation couldn't be further from the truth, its maker is right on its tail.

The pig in a desperate attempt, made a run to the Imaginary Space beyond, but it was its fatal mistake, the harmful corrosive nature of the Sea of Quanta had always put a strain on John's body, his body had always have to adapt against it, now, with that restriction removed, his body can fully concentrate to become its better self...

As the pig remembered it has a pair of wings and was planning to use it, you were already above it, staring down at it as you prepared your punch, the pig also noticed, yet it decided not to retract its wings, but rather, have made quite a smart choice.

It flapped its wings, created a giant tornado with such immense force, it also subconsciously released its powers, a lethal one against Adaptation. And you didn't get to dodge it in time, as a result, your arm was separated from you as you guard. Yet the relentless tornado did not stop at all, but only increased in intensity... As your body took in more injuries, you felt something rising in your mind, which seemed to be a work of Adaptation.

And then the tornado finally stopped. Leaving you motionless there after being blown away quite further above from the pig... The pig was about to make its escape.

Sorry, Kevin.

You started at the Imaginary Tree above, as your body was flying through the Imaginary Space slowly, with your back turned to below the Sea.

I should have treated you to another cup of ramen.

I could not help but to notice that its prices have increased due to inflation.

He reached out for his detached arm which was flowing beside him and just casually reattached it.

You... Are like her, aren't you, some sort of transcended being with extraordinary power, every cell in my body begged me to turn away from this fight before I put up this form.

He then looked down at the fleeing pig.

That explained why you could hurt me this badly just like she can.

"Throughout Quantum and Imaginary, only I am John Y/n."

The declaration was spoken out loud, only he is John Y/n, this is truly, truly our I fused my genes with an Emperor-Class Honkai Beast and gained a powerful ability called Adaptation, then got blasted all the way to the Sea of Quanta, where I met Sa, whom I fell in love with, can I win her cold heart over question mark question mark question mark.

There is actually one secret trump card up to your sleeve that you can use against these opponents, but it would put you at risk, but again if you don't use it here and now, that pig will just go around and devour more bubble worlds that you worked so hard to protect.

Adaptation is the main power of that beast, but according to the records I read it once, it was not why everyone struggled against it, it was because it was about to force everyone else to regress as well.

Adaptation and Regression, the two opposite polars yet existed within that single beast, now given over to me...

Punch

The mighty devourer fell from the Imaginary Space, into the Sea again, crashed through different layers as its powers dissipated, unable to protect it against you any longer, its Authority is losing... It crashed at last... Back to where it ascended.

Just in time, Sa arrived to witness the battle's end.
"..."

Her expression is both uncaring and confusing, with a bit of surprise as well. She has so many questions right now but she doesn't know who can explain it to her, until she sees your figure emerging atop the fell pig. Her eyes taking in every detail of your current form, trying to make a sense out of it, and with all the dots connected in her mind, she could briefly put together a reasonable story.

"Y/n." - Sa called out your name, but she felt something was off, the fragment of her power that she gave you was gone.

You glanced at her, noticing her tremendous power and Authority as the stronger Higher Existence, enough to put this little pig to shame. But Sa is raising her alarm now.

"...Y/n?" - Sa called out for you again.

Only to be responded to by you charged towards to attack her.

...

...

"I would advise you not to use it."

"Is it because of its danger?"

"That's not it, if you were to go out of control... I'm sure anyone with a proper mind will try their best to take you down. You wouldn't want to hurt your loved ones, would you?"

...

...

He opened his eyes once again, the pain in his body was gone, the familiar corrosion sensation feeding on his skin returned, yet he felt so light now... He did not remember anything, as he sat up, trying to remember things, he heard Sa's voice.

"You're awake."

You turned around immediately to see Sa, only to see that she is a bit messed up... Her hair was messier than usual, and her clothes torn and cut at several places, but her body seemed to be unaffected, it was clear that she battled someone.

Realization sank in as you looked at her more, it was clear that she fought you, you gave yourself into the heat of the battle and made her your enemy, you quickly bowed down.

"I'm so sorry! I didn't mean to..!" - You said, every word carrying a hint of regret and shame.

"It's alright." - Sa said with a dismissive voice. "What's important is that you are now yourself again."

Even though she forgave you for what you had done, you couldn't help but feel guilty...

"But..."

"It's alright, really."

Sa stood up and then examined your body, checking for all the injuries that might have not healed yet...

"Anything feel off?"

"... My body feels... Lighter than usual."

"I see."

Sa stood up again and walked away, this time she walked towards the dying pig for a few steps then stopped.

"..." - She is studying it, trying to understand how something like it can ascend to become an equal to her.

"I don't know how but... That thing was familiar to you, in regards to that otherworldly power." - You said, as you came to her side. "I had to go all out to fight it... To preserve these worlds."

"..."

Sa was silent for a moment, then she spoke.

"You could have asked me to deal with this, it was way out of your league, I was surprised that you were able to defeat it."

"..."

"Forget it, good work, Y/n." - Sa said as she patted your shoulder before walking away. "Good job protecting these worlds."

You felt happy and proud when Sa admitted that you had done a good job for her, you couldn't help but to smile, the feeling of guilt slowly faded away as being replaced with love for her... Maybe this is the time? That you truly confess to her?

As you made up your mind, you turned around, looking for Sa.

"Sa! I..." - You called out her name, and were all prepared to say these words... Yet you were not prepared for what you are going to see.

An entire bubble world is being deconstructed right in front of your very eyes, you could both see and hear the screams of people as their body dissolves into Quantum Energy, alongside with the landscapes, and everything else on that world, slowly converted into Quantum Energy... Until they were united into a flow of energy, flowing to none other than Sa.

At that split moment, you were reminded of how the pig devoured the bubble world from earlier.

"... What?" - You asked in disbelief, not believing what you just saw. "Why...?"

Sa looked at you, taking in your shocked expression and looked slightly puzzled herself.

"Why? Helping you out of that state consumed quite a bit of my power... I need to replenish..." - Sa said, as she was about to turn away, you grabbed her hand, not letting her go just yet.

"I mean why... I thought... I thought we were going to protect them... All these worlds!"

"..."

Sa turned back, she looked at you in the eyes. As she fully understood what you meant, she felt a hint of guilt, evident by the look in her eyes.

"... I thought you knew."

"Knew? Knew what?"

"... Y/n, the real reason I have you to protect these worlds... Was for me to take their value of energy for myself, for my dream to rebuild my homeland."