Deep in a forest
In a cave in a forest you see to men standing in front of a woman with two infant children in her arms, one has blue flames covering him is Rin while another is a sickly pale is Yukio and the woman is dead. Then a tall old looking man with glasses with crosses on the strings black robes and a sword whose name is Shiro Fujimoto steps forward while unsheathing and raising the sword and says, "Now it is time to kill the son of Satan!". But then something happened that he didn't expect the boy with the flames smiled at him. This caused him to stop and say, "He smiled at me the one with the flames I am about to kill him and he smiled at me". He lowers the sword and tells his friend, "I can't bring myself to kill a child but I can't him either what should we do Mephisto?".
His friend Mephisto Pheles a tall man with almost purple hair, green eyes and almost dressed like a weird looking clown says to him, "I have an idea but I will only use it on the one with the flames he could be trouble if his demonic powers awaken here but first ine sphine drine" and suddenly the flames on Rin go straight into the sword Kurikara also known as The Koma Sword a demon slaying sword. "There that way he won't be flaming up so sealed his demonic heart in The Koma Sword, now for part two of my plan I am going to take the boy to another dimension that is neither Ascia or Gehenna, but an entirely different one called Remnant to someone who owes me a favor she will raise the child."
"Are you sure about this?" Shiro asks.
"Oh certainly it will definitely be better than here now I will be taking the boy and The Koma Sword with me incase he might need his powers he can use them." Mephisto says he grabs the boy and the sword. "Now then ine sphine drine." and in a puff of smoke the just disappear.
The World of Remnant the City of Vale
In the city of remnant at the house of one Glynda Goodwitch a tall blond haired woman wearing a white blouse, black skirt and pants, heels and a cape holding her weapon a riding crop to help with her semblance telecanieus Mephisto shows up and knocks on her door she opens up and immediately scowls at him and then sees the baby and the sword and raises an eyebrow and asks, "What's with the kid and the sword?"
He tells her, "oh nothing just here because you owe me a favor and now it is time to pay up because I want you to be this boy's mother."
A look of surprise can be seen on her face as she yells, "WHAT?! I am not qualified to be a mother and yet you expect me to raise him and you still haven't told me what the sword is for?" She yells and also wake up little Rin which cause her motherly instincts to kick in and grab him and start rocking him and lulling him back to sleep.
"Well you what do you know you are qualified to be a mother." He says and she takes her eyes of Rin to scowl at him. "Well the reason for the sword is because this boy is no ordinary boy he is the son of Satan and this sword which is called Kurikara aka The Koma Sword a demon slaying sword contains his demonic heart and powers if he ever draws the sword he can never again be human.", he tells her and she couldn't help but feel sad for the boy. "So that is why i bring him to you if he is here than he won't have to worry about exorcist trying to kill here he is safer then he would be at Ascia but just to warn you demons and possibly even Satan himself will come after young Rin here so be careful.", he warns her.
"Alright I will take care of him and I will make sure he is safe", she says as she takes the sword and hides it away.
"Very good now then I shall leave you with enough supplies to take care of the boy for at least two weeks after that you will have to get the supplies ine sphine drine", he tells her and then poof baby supplies just suddenly appears in the living room "Now then your debt has been payed good luck taking care of Rin and here is my number if you need help with him controlling his demonic powers", he says as he hands her a piece of paper with his number and then disappears in a puff of smoke leaving Glynda alone with Rin.
"Rin huh that's a nice well Rin it looks like it is just you and me and no matter what I will always love you my son demon or not", she says she kisses his forehead and she takes him into her bedroom and they both go to sleep for the night.
