To be honest, I want to use the original story of Jack the ripper where she is a normal girl slowly becoming a serial killer but I think won't fit the storyline because... I don't know how to manage the years;-;
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(3rd POV)
*Whistle noise*
Cain is walking calmly on the road in London while wearing a man's suit in the past, he has hidden his true body inside the blank ID and turned off his presence concealment skill to make sure everyone is aware of his presence.
What is he doing? He is holding a map, a map of the old London city and talking to himself "What a pain, I'm currently in 1880, eight years early until the fourth singularity happens. *sigh*" He let out a disappointed sigh and continue walking.
He constantly looks at the map he is holding while walking, "Let's see, Whitechapel district, a big river... oh, I'm here." Cain stopped and look at the river in front of him with great interest.
"Hm, let's see... the loli Jack the ripper true nature is that of a collection of wraiths born from the aborted children of prostitutes in Whitechapel, London. Once the number of aborted children who were disposed of in rivers reached the ten-thousands, the collection of resentment that the children shared eventually formed the shape of a human. That is what the system said." Cain mumbles silently.
"Better act at night, it's time to find a room to stay."
After renting a room, Cain put his suit away and wear his usual clothes, simply because the suit is too uncomfortable for him. He open the window and look at the crowded street, feeling nothing at all.
He let out a long sigh again "everything is so meaningless to me, I can't even feel joy or bored. Haiz... while there aren't any actions life is so meaningless to me." Then he dropped himself on the bed.
"I can't even sleep... guess being a weapon has a lot of flaws eh? I can't sleep to regenerate my HP and MP like the manga."
It's just another episode of Cain complaining, cursing his life, nothing to see here.
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(Cain POV) {night time}
It's nighttime, the perfect time for a thief- I mean an assassin like me to act. Welp, it's time for me to test out the strongest skill I have now: manifest.
I don't want to wait for the number of abortion children to reach 10 thousand since that will be too problematic and I can't track the progress, the other reason is that I don't like to see those whore throwing away their own children since I still have some standard and a strand of humanity left in my body... or at least that is what I thought.
Why I'm standing here and talking to myself again? Nah, I'm technically an immortal so I have a lot of time to spend, monologuing aside, I have a child to create...
That sound seriously wrong on many levels. I will slap myself in the face.
"Hey, do you hear anything?" Oh, the old London's police! Haven't seen any police in years.
"I think I did, it sounds like a metal crashing together." Body made of weapon, yay.
"Let's check it out, I think it comes from over there." Just do your work Mr police, I'm going to go past you like a ghost.
Now back to the main job, seems like there are already quite a lot of wraiths in the river and all of them is swirling together and making something look like a tornado.
Now... how do I create Jack-chan without making a mistake? There are approximately 8000~9000 unborn children wraiths in the river, waiting for their... comrade to join in.
Hey System, is there any chance for those wraiths to form a body for their own?
[There is a 1/100000 for those wraiths to form a body because they are lacking a certain amount of resentment.]
... I see, that is why Jack in the Fate series want to return to their mother's womb, their resentment makes a human body that contains ten-thousand unborn children's wish, they wish to be returned to their mother's womb.
[You are correct, but missing a few details. The body is an amalgamation of evil spirits so they tend to be somewhat cruel so you should be careful if you want to adopt them, or lewd them]
Oi! I'm not a lolicon!
[Yes you are, at least in your last life.]
Whatever, I'm going to use Yin Yang creation and Manifest to create a body for them, it might be perfect since Yin Yang creation doesn't create life form but is still able to create soul and intelligence, I can also purify the soul but still keep their resentment. Manifest, on the other hand, can manifest anything I want so I can just create a living body to store those resentments if it's necessary.
"No matter what, I'm gonna bring this little girl with me, she is too cute to be left dead by the time. Void magic: World of the lost." I used my skill and open a box that covered the whole Whitechapel district, every lifeform that is under half of my levels will be forced put to sleep, it also blocks any light from coming out of the box so no one from the other districts will notice.
Now, Sage of Six paths transformation and take out Samehada, the sword which I didn't use to fight but to store MP for some big event like this. Now everything has been set, it's time for the big performance my lady and gentleman!
I don't know why but that sound old like Kakuzu, whatever.
Using Yin Yang creation to create some necessary stuff for her and purify their evil thought, or at least some of them, I want to keep the original Jack the ripper personality a bit since she is... cuter with that personality, although I don't want to become her mommy.
Manifest a body for all of the Wraiths (souls?) to stay inside and then give them a lot of power, mainly dark magic knowledge and present concealment skill since I wanna make little Jack become even more overpowered in this version... If I remember right, her 3 active skills are basically: dodging, buff removal and healing.
While they are indeed good but I don't think it's enough, her only passive skill is presence concealment A+ rank isn't enough too, I will create one of the most overpowered Jack the ripper ever then raise her as my daughter.
Pretty sure that is not how a weapon supposes to work out but Nah, who cares? As a weapon, I can lewd the loli without being stopped by the FBI since there is no rule for a weapon to lewd the loli.
And technically I'm genderless too... Nevermind
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(3rd POV) {several hours later}
"I wanted to say r/Woooosh right now, I have done it! I have created a child- I mean I have created a human by myself, a perfect human body for Jack-chan but with a power rival a servant." Cain proudly laughed and look at Jack's naked body lying on the floor.
"... crap, I should bring her body back, or else someone might be misunderstood I just harassed a little girl," Cain mumble and pick up Jack's body and dispel his spell then disappear from the view
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Author side:
Alaya and Gaia situation: clearly unaware of Cain because he is just a weapon, no matter how did you look at him he is just a weapon.
Chaldea situation: they are going to get fucked up pretty hard if I have to say.
Solomon: might survive
Goetia: can be worst than dead
Jack-chan: overpowered, loved and more of a killer than ever.
Universe combining: Record of Ragnarok and Fate. Jack the Ripper vs Hercules! Jack win by using magic XD