One of the biggest hurdles of progress in human history was the lack of proper machines to observe the world. People were often creating wild theories with inconsistent data just to somehow create an illusion of understanding.

Take for an example early depictions of world building. They ranged from living on a giant tortoises to some celestial terracentric configurations

Philosophers from ages past tried to explain natural phenomena by different means, some more esoteric, some more scientific, but all of them were using speculations and mysticism of how they think the world works.

With time and breakthroughs came the evidence, the empirical data, which some of the brightest minds of that era could use to craft new theories. One could say that humanity started requiring proof that the theories someone is presenting are good depictions of reality.

In the Mushoku Tensei world it is very scarce practice for people to manipulate mana directly, rather than just invoke spells and push mana into them. In other worlds, because they lack this crucial skill they are yet to observe that Mana is really good at one thing.

Observing reality.

Indeed, without magic one has to go through a series of engineering difficulties and age progression to craft more reliable tools required for observation of the miniature world.

The most prevalent medium at the beginning was light, so people created magnifying glass, then came a series of breakthroughs with ever progressing microscopes, where people for the first time started to see bacteria and microorganisms.

Yet, it rather quickly became apparent that visible light has a certain range, at which objects smaller than it won't refract it or become destroyed by it, so we can't observe atomic ranges directly..

But humanity found other ways, like electron microscopy.

Anyway, when Rudeus started to experiment with different techniques of magnification, it quickly became apparent that magic is a very good medium for scaling up magnification up to subatomic ranges. Moreover, it gave a direct means of affecting them, and making large scale conversions.

In other words it was any biological major wet dream.

Instead of having to take ages to see effects of mutations and waiting till the new generation grows up, one can change fundamental blocks of one organism in a matter of seconds in a controlled way. In fact, with lots of grinding on subatomic level Rudeus has been doing in his 3rd year of life, came down to practising and observing this changes.

Tests of such nature require quite a large number of specimens, which thankfully there was not lack of near the village. Every day Watch had to keep this and nearby villages safe from literal infestations of monsters, monsters which Rudeus was quickly capturing and cross referencing their DNA, different composite protein strands, their origin's of magic themselves.

What magic was also good at was scaling up simple algorithms to big data science, so doing things like crossrefencing genomes of the similar species, replacing and finding similar sequences and replicating the organic material from magic from scratch.

Dealing with such a giant amount of Data also required Rudeus to create special conceptual anchor to a stone tablet that he could recreate and summon with magic, that served as a mnemonic device, which held all of the collected biological samples from all the monsters, from which he could perform necessary operations

The last thing in biological modifications that has helped him a lot, was that he could literally train his magic at it. Which means the following, imagine that there are species of a wolf with dark brown hair and grey hair, now, after locating the exact genes in DNA which caused the particular change and replacing them, then doing the same for tens of different species and growing proficient with it. He could on the fly change the colour of any species already encountered to anything he wanted.

His magnum opus in that regard was a neon bright rgb changing colour hair, which he has also done with eyes. Further experiments with different genes made much of his analytical work obsolete, as his magic by itself started to get better at getting what he wanted implemented in DNA and scaling it up to the whole organism.

It is like that feeling in your brain, when something starts clicking together and you can do it subconsciously without thinking much about the undergoing process, just focusing on variations and desired results.

Therefore, after flying through the kingdom and locating several different bandit and kidnappers camps, he had the last specimen he wanted to have experience in manipulating with. The sapient beings. He has found some humans and Elves, and even some beastmen, from which all of them he has incorporated the best boosted genes he could have into himself.

Rudues has been experimenting with a particular turtle for more than a month now. As far as his mastery with biological matters were going on smoothly, his master with the magic capacity and its regeneration were only starting.

Hence his last project so far, he has been trying to grow the turtle's magic capacity and imprint on it his latest spell of teleportation, which he has developed.

Although he has been successful with using the spell to teleport small objects, he himself was still hesitant to test it himself, therefore he wanted to use this turtle as the test subject for both of those things.

He was currently literally sitting on the surface of the paddle in his home. His turtle was also walking on the surface, as Rudeus has already made its mind used to using the magic of sticking and walking on surfaces and water.

However, he was now performing the latest arrangements of making it as easy for the turtle to teleport as it was for it to breathe.

"Finally." he sighed observing the final result with anticipation.

His turtle Jerry has just lifted his head a little looking at Rudeus before promptly disappearing.

Having all the senses active, Rudeus used his flying to soar into the sky and pinpointed the location where the turtle had landed upon.

Apparently on some kid's head.

Using supersonic speeds with special modifications to make the wind stable, he appeared behind the kids, catching one of them, who was about to fall, after looking at him.

Which in turn, made another kid fall who he caught with telekinesis. As the kids were reacting to the display of magic he was making, he reached for the turtle, only for it to disappear again.

He cursed, then he looked at the children again, so he tried to minimise the damage, but he cursed again.

'Whatever' He thought, rolling his eyes and going to the next location where the turtle was.

"Maybe giving it ultra fast mana and stamina regeneration with all range teleportation skill wasn't the best idea, in hindsight." Was his final thought, after a whole day of goose chasing across the kingdom.

At the end of the day, he gave up and returned home, only to then have the turtle teleport in his paddle and start to calmly eat the pond algae.

'Whatever' He huffed. 'The turtle had a tracing spell on him anyway.'

So the tales all across the kingdom of a teleporting turtle has started. Magic guild and several noblemen have issued high rewards for capturing it, yet no matter how skillful someone was, the moment the turtle was in any danger of being caught or incapacitated it has already teleported somewhere else.

As Rudy was experimenting with a monster, suddenly a black portal manifested with a slender person aiming a concentrated beam of magic at him.

Just as Rudeus started to teleport, he found himself rooted in space, but before the attack fired, out of nowhere another hand gripped the attacker's hand, followed by the blanket of space tearing itself and showing off an edgy muscular teen-hulk with a rainbow colour changing hair and eyes.

The attacker didn't even have time to scream, before completely disappearing. The man then looked at Rudy and sneered. "Really, can't you even deal with your own problems?"

Rudeus shrugged and replied, "Work in progress, btw. you know how ridiculously cringey you look, right?"

The man showed him middle finger, before monologuing "Then work faster, I was quite surprised that someone was able to breach my defences." He went back to staring at the black portal.

"So what kind of world?" Rudy asked with anticipation.

"Many worlds theory." the older man grumbled.

Rudeus spat, "Shit, and no shit." staring a little at the ground, before stating"So I have not become the owner of the multiverse."

The man looked back at him, saying "No, not in total, anyway, maybe in a local bubble, where you can't perceive anything more, but bubbles can grow infinitely. Any timeline exists, so there exist those where you conquered multiverses, those were some other people conquered them, those were you fought those people, even the kids in this villages have their own multiverses, where one can find infinitely ascending chain of bubbles, and then infinite chains of those, and those, and one can go like that the same like with cardinal numbers."

Rudeus pondered for a second, "Well, it sucks, so always only local levels of supremacy and being Eldritch Abominations, until you get consumed by a larger collective or other rivals. Well probability goes to 1."

"Nah, you can live your life as a series of episodes, even infinitely, it wouldn't matter much, when you go more into complexity you can always create avatars of yourself to enjoy different levels of life."

"Then, if saving my life is inconsequential as anything exists anyway, why are you here again?"

"Hmm, even though me and our alternate selves are jerks, we have made this collective bubble's past quite secured by preventing machinations of others, this guy here has breached our collective defences, so we wanted to know how he did it. If it was an alternate version of me going after you, I wouldn't want to risk my life to even know how he did it." His alternate future version shrugged unapologetically.

"So, let me guess you have no idea how he has done it and you are just staring in space to bullshit me. Also have you already enslaved my mind to your collective?"

"Nope, I'm reading history logs of magic of this place in the World. About your mind, you're completely correct, you won't go against me and in fact will support me by transmitting all your knowledge and experiences to me all the time."

"Meh, I would do the same." Rudeus shrugged.

"I know." His older self shrugged as well.

"So, any advice?" Asked the younger version of himself.

"Hmm, reinforce the double helix with golden strands, definitely before "I am atomic" research. Immortal demons are partially immortal because they have their DNA suffused in magic all the time. Also try to improve the double helix to more dimensions and other types of amino acids with more connections. Besides that, dunno, don't teleport to the sun or create a black hole to test your defences for quite a while."

As he ended his speech, his older self started casting the black portals, which the previous person used, before saying. "Neat."

Then they looked at each other in silence.

"So, brain in the jar, huh?" Reduce broke the silence..

"Basically" Alternate Future Rudeus snorted.

"Therefore, it also means that we are just in some stupid fanfiction read by some reader. Hmm, then Dear Reader, I would like to thank you for reading this story."

(You POV)

"Hmm, then Dear Reader, I would like to thank you for reading this story."

'I stare at the screen, yet there is nothing more to be found, just a line break…'

Every day for the last couple of weeks Lillia was finding a little excuse to walk a little away from the mansion to sneak peeks in the distance if anyone was waiting near the white ruined house in the rear of the village.

She had a nice viewpoint of that place, so she didn't have to waste much time to go there and confirm if anyone was there.

This time around, it was different, a donkey stood by the ruins. Beside it? A figure with what seemed like a wizard's pointy hat and staff.

Suspicion clawed at her, not knowing if it was somehow a setup created by Rudeus, who has discovered the poster. TTherefore, she has stealthily sidled from the side, trying not to give away any sound.

When thinking about Rudeness, she could say that for the first three years he was quite an oxymoron. Since early days he was jumping around and pranking people, doing some mischievous and heartwarming activities. Though, largely liking to keep to his own and sleeping most of the time, which was kind of contrary to his sudden sprouts of activity.

Nevertheless, it made her consider him maybe a blessed child, gifted with some greater physique, or maybe cursed one because either it tired him easily, or for some reason he had required much longer amounts of sleep than normal.

Nothing too spooky, just her luck.

But then, when he turned three years old, she had suddenly heard that he can heal people, summon some lightning dragons and beat his father in a swordplay.

That… was too weird. She has been at that time provisioning for necessary cooking ingredients, so she has missed the supposed display. But Rudeus'es concurrent everyday sparring with Master Paul made her pay significantly more attention to his actions.

It was innocuous at first, but then she has observed that the way he talks is often so… measured, calculative at best and manipulative at worst. Which made her often wonder about those solitary moments alone in his room.

As she paid more attention, he suddenly started disappearing, allegedly 'playing' somewhere in the village. Yet suspiciously, none of the other children or villagers knew what he was doing.

That led her to believe that he was going to the forest monster hunting, and indeed when she asked/interrogated Master Paul during one of the meals he has mentioned that it is unusually quiet season so far and that it should be much more infested.

But then again, it made her doubt herself, she has heard a story where he was no more than two years old and defeated a monster. Seeing that he can already match his father, the Advanced Swordsman in all schools… just maybe he was going to the forest to further hone himself.

When she suggested that maybe it is Redeus who is killing those monsters, Master Paul started to consider it really hard, but then laughed it off saying that his son is so good that he doesn't mind if that is the case, but agreed to investigate anyway… more for the reason of teaching his son about seeking permission than actual concern

In conclusion both parents were really mad at him, but he wiggled a permission anyway, claiming he has been doing it consistently for months already.

If that was all, she would let it drop, but it didn't end there, after some time Rudeus began to transform. He grew taller, stronger, with a face so symmetrical, it was eerie. He began to exhibit strange habits, terrifying kids, and prancing about, recruiting for his 'cult'.

…And she was convinced that she had seen his pet turtle sometimes appearing and disappearing in certain places around the manor!

She was definitely not mad! She shook her head, observing what was a blue hair teenage girl in mage's outfit, biting her lip and gathering her resolve.

But that was not all, no, the most unnerving transformation of all; Rudeus returned one day, his features altered to a haunting whiteness with his eyes and hair changing colour, like a demon. He brushed it off as a magical makeover, and his parents? They just accepted it! 'Typical Rudeus' they'd say, or 'our gifted child'.

Master Paul had even the nerve to suggest that some demon ladies would love that! For which he received the deserved smack to the head by his wife. Therefore, at that moment Lilia has decided that she is the only sane person in this household.

Therefore, no, she couldn't let the naive Zenith and stupid Paul be controlled by this demon. He had them on the whim of his finger, they stopped questioning any weird things happening to their son and just started shrugging and saying 'let him do what he wants'.

With these unsettling memories, Lillia's determination solidified. Approaching the blue-haired mage, now with a pain-free stride thanks to it somehow starting to heal several years ago, she introduced herself.

"Welcome" Lillia began, taking a deep breath, "I'm Lillia, maid at the Greyrat mansion." She hesitated, before adding. "I'm the one who issued the quest."

The blue-haired teenage girl, adorned in mage's garb, looked up and assessed Lillia with curious eyes. She took off her hat, before introducing herself "Roxy Migurdia, Water Saint Magician," and adding "yes, I'm interested in this quest."

Lilia bit her lip, before going into narration of her discoveries and concerns. Roxy let her talk about everything before confirming "Hmm, I have verified some of the information with the people in the nearest town, but the sudden transformation as you call it of hair and skin seems to be unheard off there."

She thought for a second, biting her nail, "The most concerning fact is supposedly him being able to fly and summon elemental dragons on the fly," then she added carefully, "in fact, if that is true, I sincerely doubt I would be able to do anything to stop him and I also consider it quite impossible to be achieved by a five year old child."

Lilia was crestfallen after hearing her, dropping her head and preparing for rejection, but-" However, all testimonies have mentioned him being non aggressive and not violent, just a little mischievous, have you observed any worrying signs?"

Lilia thought about it for the second, but beyond being manipulative and fighting monsters, which she has mentioned, she had no clues, so she replied. "No, as far as I know, he only does harmless jump scares."

Roxy then nodded and exclaimed, "Right! Therefore, there should be minimal risk of me approaching him and asking a few questions, therefore… I accept the quest!" Roxy nodded.

Lilia then didn;t bother to mention that they didn;t agree on a price yet, she didn't have much, saving just a little over months from which she didn't send her parents, so she was lucky she could claim ignorance later on.

As Rudeus was returning from his Ranoa debut as the Eldritch God of Magic, he sensed an unusual presence of a mage in his house. Further observations, through walls, from several kilometres, found out that it was Roxy. Because who else besides the Migurd tribe could look like that?

Therefore, he literally teleported to the table where she was sitting and discussed it with his parents, sitting right next to her.

He had done it seamlessly, without any flashes, sounds or movement of the air.

His parents, being opposite of him at the table, of course noticed him, so as their eyes turned to him and naturally, the confused at the shift in their reaction, Roxy followed their gaze to where they were staring, she went all, "Waahh!" flimsy waving her hands and about to fall off the chair.

Thankfully, Rudeus did hold her with telekinesis in the air and reaffirmed her to her seat.

She blinked owlishly for several seconds, before blushing slightly and making a small cough of regaining composure. "Ugh, thank you. I presume you are Rudeus, right?" She looked at him curiously.

'It seemed what the maid had said was real, she and his parents didn't see him arriving, so the claim of a teleporting turtle didn't seem so far-fetched. The same with his exaggerated cosmetics.' she analysed, not knowing what to do with it.

It was not like she could cast anything beyond mid level expel curse spell. She had some broad knowledge of curses or blessings but none so apparently matched the case.

'Though, there were some legends of Immortal Dragon race reincarnating and influencing the looks of their new bodies.' she mentally remarked, latching onto that.

She was thinking that, while Rudeus replied to her question. "Yes, and are you perchance of the Migurd race?"

She blinked at him, thinking, 'maybe a reincarnated Demon, then.' nevertheless she replied. "Yes, that is correct, though it is surprising that anyone this far would recognize me."

Implicitly she asked. 'How do you know it?', to which Rudeus replied. "Hm, I have just guessed, because I have read about abilities of different races of the continent at various bookstores in Ranoa Academy. Migurds are described as those with blue hair and having an ability to mentally communicate with each other."

Well, her mood soured at that, as unpleasant memories returned to the forefront of her mind. Nevertheless she sighed and confirmed. "Yes, you are right, though unfortunately I have never inherited that ability."

She looked melancholy at Paul and Zenith and felt in a mood of sharing some of her troubles, therefore she opened herself more. "It is one of the reasons I have decided to leave."

There was little silence, before Zenith beckoned to Lillia, "Lilia, if you could please fetch the red wine and glasses? Oh and also join us!"

"Yes Madam." replied curtly Lilia, before going to fetch the items.

"I'll help." announced Paul and swiftly started preparing.

Roxy felt embarrassed and raised her hands. "Ah, oh, no it is unnecessary…"

Zenith cut her off with a motherly smile, "Nonsense, my dear, it is not often that we get visitors, so just relax and feel like at home."

"Oh, uh…" Roxy replied, snuggling into the chair, before visibly giving up.

When the wine started rolling, it wasn't long before Roxy started to drunkenly reveal her most private stories "And then, that idiot, told me that I did not deserve to learn his spell and expelled me!"

Equally drunk Zenith replied. "What a prick! Right Paul?"

Paul was in far better shape, but it didn;t seem like he cared so much, so he also replied. "Absolutely!"

The trio cheered to that, while Rudeus exchanged knowing glances with Lillia who sipped her wine rather moderately.

However, instead of continuing further events, Roxy turned attention to Rudy, "Ne, how come you have these strange colours on you, are you some sort of reincarnated demon?" she asked, before covering her mouth with hand and saying. "Ups, wasn't supposed to… 'hmph'" She hiccuped.

Rudeus thought over what to say, before replying. "Nah, I used magic to make cosmetic changes. Interested?"

Roxy immediately replied, "Yeah, I know no magic that can do that." she was swaying in the chair.

Paul snorted, cutting in. "He probably created it on his own."

Zenith flushed and exclaimed. "My genius boy!"

Rudeus replied, "Yes, I have created it myself. Wanna see how it works?", he then changed his hair to long blue locks like Roxy and changed his eye and skin colour to match hers.

Roxy was visibly surprised, but Zenith replied. "You look much better like that Rudy!" Then she elbowed Paul, asking,"We have two Roxies now, better take responsibility!", before erupting in laughter.

Rudeus then felt a little mischievous and through application of his magic changed everyone's hair and eyes to that of Roxy.

"Pfft. Now we are all like Roxy!" he snickered

Rudues, Paul and Zenith erupted in laughter seeing each other, Lilia became pale as ghost as she was inspecting her hair, while Roxy became a miniature ball of fire trying to collapse herself from embarrassment.

Naturally, Rudeus took this moment to say, "I'll go play with my turtle, cya!" before disappearing.

"Hey, revert it back!" Paul shouted, but it fell into deaf ears.

There was little silence, before Zenith said, "Fuck it!", before chugging all the wine in her book and slamming it into a table she said "We can all be Roxy tonight! Come on, what happened after the prick kicked you out!"

Roxy whined meekly from embarrassment, before continuing storytelling.

Rudeus, in fact, didn't go play with a turtle. He wanted to do the research on the obtained blood and inside its DNA of Roxy. In particular finding out if there are any interesting inactive genes, like her Mind communications, which he could activate and incorporate into himself.

Yet he would do that tomorrow probably, testing them out on Roxy herself, after little convincing. It is not like he had any captivies or bodies laying around for experimentation and he didn't really feel like it to go and seek some bandits at the moment. As he seemed to have eradicated most of them in a two hundred kilometre radius.

Instead he spent the gruesome work of categorising with his current database thousands of genes present in Roxy, looking for new sequences, and minute differences with old ones.

Configurations of genes weren't easy, some combinations did lead to disastrous outcomes. In theory he could practise them on himself, as he would most probably be able to reverse it before the subject dies.

He had only begun experimenting with souls, so he wasn't yet successful in recapturing souls of dead bodies and reanimating them, so it would be the worst outcome. But activating genes one by one shouldn't pose a greater problem if only for a second or two, where he would use healing magic to artificially apply changes, see results and in the worst case reverse everything.

He had a lot of calculations to do…

Roxy took a lot of time snuggling in the bedsheet, before slowly getting up with a yawn and opening her eyes.

She was… in a small room, in a bed, alone. The sky up in the sky indicated that it was closer to noon, then the morning.

She felt a little embarrassed remembering the previous day

Greyrats were good people, she decided, even though she understood the concerns of the maid Lilia about their son and his prodigious talent with magic, she didn't know how she would be able to shed any light into it.

"Well, I could always go and ask him things about his magic." She decided, and got up. She was still dressed in yesterday's clothing, so she went down the stairs to see that everybody else was already on legs.

She felt embarrassed again, though she came out downstairs to the main open area.

"Oh Roxy, how was night?" Asked Zenith, coming to her.

Roxy noted that yesterday's blue themed spell still affected her.

"Hello, it was really comfortable, thank you for housing me." She bowed her head a little.

"No problem, stay as long as you like." She waved her hand as if it was no concern.

As long as I like?' Roxy was surprised, but then calmed down thinking. 'Ah, it is a polite offer, but it would be rude to actually accept it.' therefore she shook her head and said. "Thank you, but I don't want to impose."

Zenith shook her head grasping her shoulders saying, "No, you don;t understand, we with Paul were also adventurers one day, so we know how hard it is sometimes, especially for someone as young as you, so you can stay however long you want, enjoy the village, maybe even teach Rudy some more saner magic. Don't worry, we can afford it." she let her go and showed her thumbs up.

Roxy stared at the ground and whispered, "I'm forty…"

"Come again?" asked Zenith, not hearing.

Roxy, still not lifting her head, mumbled a little louder "I said I'm forty years old."

Zenith whistled, before saying. "Uh… That is. Ekhm'' She coughed, before continuing "That means a little, we still offer you our home to rest, no matter your age.."

Roxy looked up at Zenith, with eyes filled with tears and seeing Zenith welcoming nature, she started sobbing and sniffling openly. Zenith just smiled and enveloped her in a hug. "Don't worry, we are here." She patted her on the back. "As long as you need us." She promised.

To which Roxy started sobbing even louder.

After pretending he didn't see anything heart warming happening at the house, Rudeus was just spending his time leisurely, leaning back on the tree with Sylphy at his side, just relaxing, while relishing the shade.

Which means that only he was relaxing, while Sylphy was admonishing him fervently about how stupid was his act of announcing himself as an Eldritch God of Magic in front of all the people.

Apparently, she has used the imprinted flying skill which Rudeus finally granted her after enduring only so much of her begging, which she used to travel by herself to Ranoa to learn magic from 'more reliable sources', as she claims.

Completely wrong, he would say, as he is the best source, but as he refuses to teach her, he will forgive her.

Sylphy exhaled deeply, her frustration evident. "But Rudy, what if your announcement brings trouble? What if a strong foe comes for you or challengers trample our village to face you?"

He decided to reassure her "Don't stress about it," he said with a dismissive wave. "I can handle it."

To that Sylphy pointed out, "And what if you are away at that time, doing something else that catches your attention? Or what if you are not fast enough and they will hurt our families, like our fathers who are at the watch sometimes kilometres away?" she asked perfectly valid questions, of course.

"I'll think of something," he courtly replied.

"Why are you doing such stupid things in the first place?" She asked, before adding. "You could have consulted me before making such a grand claim," she pointed out. "I would've told you it's a bad idea."

With a hint of annoyance, he replied "And why should I seek your validation? You're just following my lead." He dismissed her annoyed, but realising that his words came off harsher than just a joke, he snapped his eyes at Sylphy in fright, thinking. 'Wait, why the fuck did I say that? I literally want people to question my stupid decisions!' Therefore he quickly wanted to rephrase it. "I'm sorry, I meant…"

Sylphy looked taken aback, "What?!" she exclaimed, stunned.

"No, that's not what I meant…" he began, but she interrupted.

"I know what you meant. You are a self conceited prick Rudy!" she shouted, now getting up and being furious, before continuing."I've been by your side, worrying for you, and this is how you see me?" Her voice quivered with emotion.

"I was just, you know please forgive me…" he also got up showing his hands in a placating gesture.

Rudeus stepped forward, regret evident in his eyes. "I'm sorry, I didn't mean that. It was a poor attempt at humour. You know me right? I sometimes spew some bullshit I think is funny. Clearly this one was not…."

She looked away, trying to hide the tears forming in her eyes. He stepped closer to her, not knowing what to do.

After a moment of silence, she finally faced him, her expression shifting to a mischievous smirk. She tapped his forehead gently. "Gotcha, loser!