I Returned In The Past But Why It Look Different?! (Multiverse Fanfic)

Chapter 4

"Shall we practise with kissing first?" Serafall asked with a lewd smile.

"Indeed we need to run some tests on that one," Marcus said that while his hands touched both of the sexy devil lady assets.

Hearing that Serafall immediately remembered role-playing, more specifically science type ones…

So, she needs to get her hands-on some sexy glasses and lab coat… 

"Shall we commence it then?" The sexy black haired devil said with a voice that reminded Marcus of serious science ladies he worked before in his previous life.

"Test number one…" He said that as leaned to claim Serafall's lips, the moment he touched her lips the beauty pushed forwards and started a make-out session right there.

Just a few moments later her eyes already turned glassy.

Soon her hands started to wander around, as she started to undress him and her Master quickly joined in that, as he started to remove her skimpy shorts and a t-shirt.

Seconds later the kissing had to end for the simple reason that the clothes were in the way.

The moment Marcus saw Sera's underwear his eyes slightly widened as they were extremely sexy! She was dressed in black almost see-through panties and bra.

"Like these? Do you know the best part? I can dress however you want!" She gave a seductive wink.

"I will...remember that for future reference…" He said with a gulp, as he started to feel her warm body now, since they are almost naked.

"You better! I can't wait to see how you want me to dress up!" She said that with an excited smile before focusing on the matter at hand!

"And this here~~~ is for me isn't it?" Serafall said that as she licked her lips for a bit. Before pulling the last bits of clothing off her Master's body.

When she saw his rod already rock hard, a purr escaped from her lips.

"How do you want Master? Shall I serve you now? Or do you just want me like this?" She said that hotly as her hand went on his rod.

'He is still growing… this is going to be so good.' The devil lady licked her lips when she stroked her Master's cock. She already liked this! but! she realised that it's only going to get bigger in the future!

"Show me how good is Satan Leviathan at serving her Master." He said that while stroking her cheek.

"Fufufu… as you wish…" The beauty elegantly moved on her knees and started serving him.

Before long Marcus started to groan from feeling her hot lips around his shaft. And it was only the beginning as she quickly started to escalate to the next level where she started using her breasts. The bra was long gone from her as she continued to undress. While sucking on his rod.

The devil beauty very quickly started moving up and down on his shaft with rapid tempo. It almost felt like she is starving and his cock is the only food source available to her.

With a groan, Marcus came hard in her mouth and Serafall very greedily drank it all.

The inventor was quite shocked how shortly he lasted but then again his new body has no experience with females at all!

Serafall drank it all masterfully before pulling out, she looked with glee at how quickly her Master is recovering from his first release.

She stroked the shaft once more, watching how it slowly went full mast for her. Once it was ready she got up on her feet and removed her panties slowly.

Making sure Marcus saw every small detail of it.

"How do you wish to proceed with this test?~~~" She asked seductively with one hand on her hip.

But instead of receiving an answer her Master simply grabbed her and pulled her into his lap.

The black-haired devil lady simply purred more before wrapping her hands around his neck. She positioned herself perfectly to receive his rod.

Teasing with her pussy lips, moving forwards and back. This was enough for Marcus who grabbed her ass and pushed her down on his rod.

"Hhmmm~~~ that's it…" Serafall moaned when she felt invasion in her cave. Her pussy was sucking him hard. She has been waiting for this for months… she can't remember the last time she was this horny!

The simply insertion make nearly come hard!

Before long his rod was fully inside and the beauty could not control herself anymore so she started moving her hips.

At first, her movement was quite slow but speed quickly increased. As she moved her waist.

"Mmhhh~~~"

"Hnnn~~~"

"Leave this to Sera, Master~~~ this test is all mine~~~" She said that while changing position slightly leaning back, showing him her impressive rack.

Marcus hands moved on her breasts since they looked very enticing, he needs to test their elasticity.

Serafall grinned silly seeing her Master's expression, that of a very hard trying man. She was moving on his cock and he was trying hard not to come while thinking of touching her more.

Nonetheless, Marcus didn't last long against Serafall who was hungry like a beast. As before long ropes of cum rushed inside the Devil Lady womb.

"Hmmnnnn~~~ it's here… very good~~~ a very successful test~~~" The devil beauty said with glassy eyes.

"...A very successful second test… we should move to third one…" Marcus said that as she grabbed her hips. Serafall eyes slightly widened before starting to smile lewdly.

"Ohh~~~ Master sure has great vitality~~~" She said that with purr… she felt him channelling magic through his body. She wonders if Solomon has left some magic techniques for this… after all the man had a massive harem!

Before long Serafall was flipped over and was on her back, both of her legs went up.

She liked this even more since her Master is taking charge like this!

Seconds later she was already softly moaning from his movement.

The beauty wonders how much he can last? Especially since this was his first time!

~~~~~~Next Morning~~~~~~

When Marcus opened his eyes the first thing he saw was his room ceiling. Everything was normal just how he liked…

Or should be. But, he felt heat source next to him. Instead of reacting to it he took a deep breath and smelled a familiar smell of his devil girl.

He understood that Serafall decided to sleep with him. Instead of reacting to that in some weird way he just wrapped his hand around her and decided to continue to sleep since he had around an hour until he needs to wake up.

'Hmm sleeping with Sera is nice. I think I need to make this everyday thing.' With the new idea in mind, the young inventor snoozed off almost immediately after.

While Serafall who was sleeping on his side could only smile more. The reaction of his to her was something she wanted to figure out. And to her's satisfaction, it was a very positive one.

Since he liked cuddling like that it's good for her. She wrapped her hands around him as well. The black-haired devil lady decided to stay like this for a few more minutes before she will need to move.

~~~

When the alarm clock rang it was seven a clock in the morning. Marcus opened his eyes and got up from his bed. He zoomed in to the shower first thing.

After the showed he was properly woken up he dressed up his school uniform. That moment he realised that his heat source was gone. He turned around and scanned his room with his gaze.

He kept his room as simple as possible, as he prefers to customise his workshop instead of this room.

After looking around he realised that Sera was not in his bed. Meaning that she left before he woke up.

'I didn't even feel when she moved. They are sneaky naturally or I am just that deep in sleep?' He thought to himself. Since she is in the system as his familiar his barriers didn't even pick her moving.

Once he was dressed up he fixed his bed and descended to the kitchen…

The moment he arrived in the kitchen his brain stopped for a second.

He saw Serafall talking with his mother and father very animately. She had her hair done into a high ponytail and very smart glasses on. She was dressed in his school uniform making her look no older than a smart-looking sixteen-year-old girl!

That's the thing about the current Leviathan, as she can easily pass as an early adult or a late teen…

"Mark! You never said you are 'friends' with an older girl!" Marcus dad said with a grin as he on purpose said 'friends'. 

The reincarnated inventor rolled his eyes. He on purpose is trying to spend less time with his family so that it would look to the devils that he doesn't care about them that much.

Less attachment the devils know the better leverage he has. But the moment he gave some space to Serafall she took it to the next level.

And he simply knows that she has a large amount of affection towards him. His Ars Goetia is telling him that she wants to learn about his parents. Not just use them. That's why he is allowing her to act all 16-year-old cute girl who is interested in loner Marcus…

"Yes, we are for some time now. She only decided to come here because it was convenient." The teen inventor said with a sigh as he took his seat. Amusingly enough it was next to Serafall and both of his parents were grinning like idiots.

"Indeed. I know him for over a year now. Even now I still find new things about him." The black-haired disguised devil said with a smart-sounding tone. Her acting was utterly, insanely on spot. Marcus even felt a chill going down his spine. How good she was with that. It is no wonder that she is responsible for diplomatic relationships stuff... 

"I see… I thought you going to marry your BMW son if this continues like this." His father sagely said that. He already expected Marcus to marry his car.

The teen inventor rolled his eyes as he started drinking his tea.

His mother coughed with amusement while Serafall just smiled.

"Don't worry. I will make sure he doesn't do that." The current Leviathan said with assuring tone.

"We leave him in your hands then Sera." His dad said that with a serious nod. 

This made the teen groan. Why do they have to take this small inconsequential thing seriously?

~~~

"Is there are reason why you decided to insert yourself in my morning rituals?" I said with an eye roll. 

Nonetheless, I do love how she is hugging my hand and acting like a doting girlfriend.

"And why not? I have altered some of the hypnosis done by Venelana. They are much happier knowing that their son has a girlfriend!" Serafall said that to me while continuing to hug my hand.

We already are close to the school and I already started to see some people looking at the black-haired devil girl of mine.

Her beauty is supernatural, and perfectly honest I started completely dismissing regular girls when I started to see Serafall daily.

It's like they don't have that colourless, I mean I could get turned on by regular girls but actually be interested in them more than a casual thing? Not anymore…

"As long as I have my time and they are not snooping around the area behind the garage it's fine," I said with a sigh. I suppose I could accept the fact that Serafall is advertising herself to be my girlfriend.

"Don't worry. I delt with that the moment I started the hypnosis. They think that area has some miscellaneous items laying around. They won't be checking it unless some sort of cleaning is done." She explained to me.

"I see. I suppose I could make it look like that." I said with a nod thinking how to deal with it.

"Indeed. Now why don't we act like an actual couple for once!" She said with a suggesting purr.

"As long as you don't overstep your boundaries Sera. I will entertain this idea." I said with a nod.

She smiled hearing that.

"Don't worry~~~ you forget that I am a devil~~~ I adapt to any situation. I know my boundaries. I won't be interfering or demanding too much attention. But, I will be there when you are free… or more precisely you should call me when you have time… I can always help you~~~ in some way~~~" She winked seductively before entering inside the school.

I can assume she already inserted herself in the educational system of my birth country.

Hopefully the Heaven or Norse won't going to notice her profile picture… well, I don't think they have profile pictures done here yet.

~~~

"Marcus!!! Let's have dinner together!" Serafall entered my classroom with a lunchbox in hand.

I lifted my head from my notebook. And saw her smiling at me. The people who were in class were looking at me as if they saw me for the first time in their life.

I mean in this life I am much more reclusive than I was in the first one.

For obvious reason that my school attendance is nothing more to keep the charade of regular life going on.

Plus it helps me to think about things and be away from my workshop.

"Dude! You have a girlfriend!? But you never leave your desk or talk to anyone!?"

"Yeah! Like how!?" 

Some guys started talking and even have jealous looks after seeing Serafall. The devil girl's supernatural aura and looks just suck everyone in.

"Marcus is like super smart and top of the school lists~~~ did you know that he is super good with hand? Like really good?" Her words made girls blush for some reason thinking that is sexual innuendo…

"He is fixing a completely broken car from top to bottom in his free time! He like super cool and hot!" Serafall acted her part of doting girlfriend, making more people jealous…

I decided that it was time to dip the room. So, I quickly collected my stuff and left the classroom, I could feel a bunch of eyes on me especially when the black-haired devil hugged my arms tightly.

~~~

"Let's find out your taste buds Master~~~" Serafall said that as she opened the lunchbox. There were a ton of sandwiches there. 

From a single look, I can tell that each of them are different in some way.

"I have prepared multiple range of sandwiches with different tastes. This way I will find out what you like and from there I will work up to make things you like." She said that happily as she offered the sandwich to me.

"Or… you could have asked what I like…" I said that while picking a random sandwich.

"Where is fun in that? Besides this way you can find out new tastes yourself." She said that while waiting for me to taste it.

"True… let's see then…" 

I said that while taking a bite, first what I tasted was that my mouth was assaulted by spiciness which was washed over by the sauce next moment…

"This… is… good… I dislike spicy stuff but this is good! Especially this! It allows me to taste spicy stuff without burning my mouth. Very good! 10/10!" I praised her, the smile she gave me reminded me of a cute animal, if she had a tail she would wiggle it right about now.

"I know right! Anyway! Try this one!" She quickly pulled out another sandwich after I finished the first one.

'Well, this might be a good thing, My school time used to be quite dull.' 

For a second I remembered how different this time was with my previous life. Back then I had a few guys which I used to talk about cars. Since no one watched anime or plays video games…

Well, they do, only that no one talks about them in school. To embarrassing in front of girls so, we only ended discussing cars.

But, ever since I ended up in this body I didn't bother to make any sort of friends since there was no time for it.

Now with magic, it's even less possible since... well, magic, supernatural, regular people don't have a place in this and since I got myself involved with devils I would rather don't get close to any of them.

That, however, came to a question with Serafall coming to my life.

"What do you think? Are they good?" The devil lady brough me back, I turned towards her.

"This is good. All of them are nice, some better than others, I can assume you will be making them every day?" I asked with raised eyebrow since she is spoiling me like that I won't be holding back.

"All depends on you remember? You did say that I belong to you no~~~?" She asked with a coy look.

"Indeed. Then I request this daily. Since you started this trend yourself." 

"I had to, you were turning into a machine. It's up to Sera to fix it up!"

"I see… I suppose I was turning into that. But that was so that the basics could be done." I said with a sigh.

"Basics? By that, you mean to invent futuristic technology? And making barriers worthy of a pantheon level protection?" She said that while shaking her head.

"Indeed. One needs to fortify his home before moving outside." I sagely said that with a nod before starting to think about countermeasures in case Serafall action would raise suspicion.

In truth, they should have done that. Sirzechs already looking into her.

"Sera, you mentioned spies yesterday? Has anyone snooping around you lately?" I asked quite seriously and Serafall stopped in her tracks.

"Nothing of concern. Sirzechs only send some people to find out about my increased speed in paperwork. Naturally, I could not reveal anything to him since there was nothing of note in my office.

So far nothing was going on which requires us to act. But… knowing him… he won't going to stop until he finds something…

In conclusion, we should prepare something, otherwise he might push me to the point that I need to have an answer of some sort prepared for him.

Worst case he will send Grayfia after me to spy on." Serafall gave me an answer. And this was the answer I was expecting. Sirzechs will do something.

'Grayfia is an issue, she is a devil from extra house. My Ars Goetia does not affect her. That means need ro come up with another binding method. Another concept to base the binding.' 

'She is servant of Lucifer if my memory is right, Venelana barely covered the extra houses since there is very little of them left.' 

"I see in that case I need to think of countermeasures in case you need to talk," I said to her after thinking for a moment.

"...Master...I hope you not thinking to make me fight them? I might be strong but Sirzechs is on a completely different level…" 

"No such thing. There is no need for you to fight anything. Ars Goetia will pull you to my side in case you fall under some sort of suspicion. The course of action is for you to reveal that you have a contract with a genius inventor. This will cause some publicity for me, but it's better than you to lose your position.

If this comes to this we can think of future actions once we reach that point. For now, we need to think about countermeasures in case my location is discovered." I said that while continuing to think.

Serafall released a sigh of relief before thinking for a moment.

"Doesn't Diamond Heart Core makes it nearly impossible to pinpoint the coordinates of teleportation?" She asked me with a thoughtful look.

"Not quite… you will know the general direction. For example, if you are to jump from America to here. People should be able to track the general direction of it. Meaning Europe, somewhere towards Asia. This means they would be able to pinpoint that it's Eastern Europe.

It's even more accurate if you teleport from the Underworld to here. If anyone want to tract the teleportation they would know that you ended up in Eastern Europe. But that would raise suspicion as your direct location can't be tracked."

"...This means they will be suspicious because I am hiding something…" 

"Correct. That's why you need an alibi…" 

~~~~~~Underworld (some time ago)~~~~~~

A red-haired man was sitting in his office, he was radiating an extremely serious aura.

"Grayfia...I need you to find out how Serafall is doing her paperwork. It's utmost importance that you find out." The current Lucifer said with a deadly serious tone.

"Can't you just ask her how she is doing it?" His Queen asked with a confused look. She was baffled that he asked her to spy on fellow Satan!

"Already did… she multiple times dodged the question. I realised that she doesn't want to share it " The red-haired man explained to her.

"Then… there should be a reason why she doesn't want to share." Grayfia reasoned with him.

"Indeed. But, I need the truth. She finishes all her work before midday. Such a thing is unheard of. If I can do this too then I could have more time for other things than just paperwork!" He said with the last part with a chilly icy tone. His eyes slightly glowed red when he looked at a mountain of papers at the edge of his desk.

He was about to use Power of Destruction on it but changed his mind at the very last second.

"Very well. If this is what you wish. I will do this for you." 

"My thanks Grayfia." The current Lucifer nodded before returning to his work.

While his Queen left after bowing to him.

~~~~~~Few Weeks Later~~~~~~

The Strongest Queen has been trying to figure out what has been going on with Satan Leviathan.

At first, it was just her mission entrusted by her King. But now she realised that something was going on with one of the strongest members of their race.

Serafall was much happier… Not that fake Magic girl act. In truth, she has not seen Leviathan wearing a magical girl outfit for some time now.

This points towards that something is going on. With the fellow devil. Grayfia concluded that the black-haired Satan was most likely dating someone.

The happiness, the changed behaviour, she has seen these things before. But, this does not answer the question how is Serafall doing her paperwork this fast?

While the silver-haired maid didn't like the fact that she has to continue with her spying, even more, she didn't find anything solid.

This leaves with the fact that she needs to track her down in the human world…

Easier said than done. As Serafall doesn't want to be found. Secrecy to this kind of level for some reason disturbs the Silver-haired maid.

She can get the fact that Leviathan is a public person and she wants her private life, but this amount of secrecy even towards teleportation circles is over the top. No one in Underworld hides their teleportation destination to this level.

'Eastern Europe… that's dangerous Serafall, why are you going to Church controlled territory?' Grayfia tried to pinpoint the teleportation with her magic but she found out that she lost the black-haired Satan in Eastern Europe.

Nonetheless, she now knows the general location, but this might take several weeks maybe months of careful looking…

~~~~~~Marcus~~~~~~

Well, it was time to finally test the holographic design table. After finishing the basic OS the table was finally functioning to a usable level.

The whole PC and designs table was done months ago. But OS took ages to program. Even with my augmented talent. Since I was working to make it a self-updating one for sake of saving time.

There are shackles in places. I don't want a rogue A.I capable of designing tech and magic weaponry running in the supernatural world.

So, it has certain restrictions on how it can self-update. Nonetheless, it will eventually be a virtual butler capable of helping me in the field.

After thinking for a bit I decided to upgrade M.T.M Castor MK II to the next level.

For that, I scanned the paper design and uploaded it to my PC. Going through several filters I could see the 3D image of the gun.

At this level to interact with the holograms I need to wear specific gloves. These gloves collect all the data on my movement and cross-reference with the hologram. This will help to improve the hologram and the interaction from humans to the hologram.

Eventually, I won't need to wear gloves to interact with the hologram in the next level.

To reach that level though I need to use the table in the first place that's why I already using it even if it's quite uncomfortable.

First I stripped the gun of its case and only left the M.T.M circle technique.

Then upgraded the M.T.M to the next level, with more accelerator circles, magnifying circles, as well as booster ones. This made the system much bigger but that's the point.

The gun will be bigger, if the gun is bigger then the rail can be longer. The longer the rail the more power it can create.

Speaking of the rail. Next is the Barrier Rail Technique, or in this case Barrier Rail System.

As for this one I decided to make diamond rails powered by magic. Not only it will accelerate it even further, it will generate heat and friction both of which will be absorbed by the barriers around and then added the load at the very end.

This whole thing would increase the power of the shot from around 300% to 400%. In other words, even a regular man technically could kill a high-class Devil by this point. Just by pressing the trigger.

While all this was nothing more than upgrading already existing techniques or in this case systems I started working on the cartridge system.

The basics were quite easy. Scatter fire, or beam version. Or even canon fire. Those are simple magic manipulation. Done through a circle.

That's why it was time for me to summon my first devil familiar…

"Well, I am almost done with the internal design…"I said to Serafall who was doing her paperwork.

"Hmm? That was quick… I thought you going to spend days on it." The current Leviathan said with a curious look as she just pressed YES to sign a paper.

"As if… I am not doing this on paper anymore. And I already reworked the two main points of it, and now I am working on the cartridge. For that, I will need to summon Venelana." My words stopped Serafall In her tracks.

"What...for?"

"Her Power of Destruction," I said plainly. And Sera sighed in relief after hearing that. Is she jealous or something? Or she thinks that I will have my way with that brown-haired devil lady?

"I see… are you planning to recreate it?" She asked me after realising what this means.

"Indeed. More like synthesising." I said to her. Before focusing on my Ars Goetia and connecting to Venelana.

'Venelana it's me. I will be summoning you soon get ready.'

'O-Of course…' I got a shocked response from her. Well, I would be shocked too after not talking for more than a few years.

A few moments later the Solomon's circle appeared and Venelana appeared in all of her physics-defying glory.

The first thing she did was obviously to look around. Her eyes eventually ended up on Satan Leviathan…

"L-L-Lady Leviathan!? Y-You are here!? D-Does this means…"

"I am his Sitri Pillar." Serafall casually nodded at Venelana.

"No...wonder… no...wonder I was not summoned anymore…" the brown-haired devil lady was looking at the tiled floor. Her shock was obvious on her face.

"Not that you need to be summoned… you can summon yourself. I do that every day. I am the one who keeps him company any way he wants…" Serafall words had many meanings and it would seem Venelana understood that very well.

"Anyway. Let's keep this short. I only need some of your power of destruction. Once I scanned it you can return to the Underworld." I got her attention back with my words.

She turned around and looked at me from top to bottom. A bunch of emotions went through her eyes that moment.

"It's fine. I have more than enough free time nowadays. I haven't seen you Master for more than two years." She said that with a certain tone.

If she doesn't want me to leave that means there is a hidden motive. Well, we will see what is that she want. It would be interesting to find out…

'I should have asked Serafall on the political landscape of the devil politics.' For a second I thought about it. But decided to drop it for time being.

"I see… then you can stay if you want. Let's get the Power of Destruction reading done first." I motioned for her to come over where a white circle is preparing.

"I need you to create a ball of Power of Destruction and make it float inside that circle for a certain amount of time. Can you do it?" I asked her while walking over to my computer.

I could see that the circle was properly connected to my PC.

"Easy enough. I can assume you are trying to re-create it? While I have no doubt you can do it. You do know the repercussions of doing it?" Venelana asked me with a sigh.

"I have Satan responsible for the diplomatic relationships in my garage. I know more than I need." I said with an eye roll.

"If you say so…"