A/N Spoilers for Infinity War and Endgame!
Prologue:
Kamar-taj was a lot more empty after the snap even after four years. While there had been a few more recruits coming in to learn sorcery half of there number had been taken by the snap and a lot of others had left to help family or on other personal matters.
The only good thing about the snap was that it didn't discriminate, while half of the sorcerers were gone so were half of their enemies. But the snap was a truly terrible event and many sorcerers in the various sanctums had come together to try and find a way of reversing it or just bringing back all the people that had been dusted.
The group had found a way to do it 2 years ago buried in the immense library in a book that had been hidden for whoever knows how long as even the new librarian after Wong hadn't known about it. The book spoke of a method of going back in time, not physically but by casting the soul of the body and merging it with a younger version of yourself in their 13th year of life.
The method itself wasn't too hard but figuring out the person that would be sent back as there were only enough ingredients for one person. After debating over it for two years they finally decided upon a woman called Katherine Pierce.
Katherine was one of many that had volunteered but she managed to convince the others in the group that it should be her as she had nothing to lose. Even before the snap she had no family or any close friends so those around her won't notice how much she had changed over the years.
As they had been deciding who would go back they had been collecting copies of all of the books in the sanctums for a multitude of reasons, the first being that a thirteen year old wouldn't be able to get into any of the sanctums very easily. Another reason was that after the spell/ritual that would send her back in time there was a warning that said how there was a very small chance that the person using the spell would get lost in the multiverse and merge with an alternate version of herself.
With that in mind and how the books would be needed anyway they searched for a way to allow Katherine to take them and a few other items with her and eventually came up with a small pocket dimension that would be connected to her soul and allow her to call upon it whenever she wants to.
Katherine though was a very paranoid person and she made sure that she had a lot of items included that would allow her to be fine and help her in her mission to return 50% of the universe to where they were supposed to be. The items that she had included to the list ranged from a couple of spare sling rings to clothes that would fit her from the age of about 11 to 30 and she took advantage of a couple of empty book stores and stole their contents to add so she would have books to read in her downtime to keep her sanity.
The year Katherine would be landing in would be 1979 which should be plenty of time for her to become powerful enough to help fight Thanos and to gather allies to stop the snap from happening.
On the day of the spell/ritual all of the sorcerers had gathered in the Kamar-taj sanctum where Katherine would set off to change this future and stop it from happening.
After a few last minute checks and surprisingly enough a few gifts given to her from other sorcerers with the intention to help her were placed inside her pocket dimension she was ready.
Katherine headed to the centre of the courtyard where all of the necessary runes had been drawn precisely in chalk by the best and most knowledgeable in runes surrounded by seven braziers that were lit with green flames and burning a mixture of demon blood and other rare and foul ingredients, she sat at the exact centre and closing her eyes headed into a deep trance.
After entering the trance she started to chant the necessary words in a perfect recitation of what was in the book and each time she hit a crescendo the flames of the braziers would pulse and become a beautiful royal purple before returning to green.
As Katherine chanted the last words the flames pulsed a royal purple one last time before intensifying and then extinguishing themselves. As the flames disappeared Katherine fell back like a puppet whose strings had cut in a burst of blinding white light.
The spell/ritual had worked.
After she had completed the spell/ritual Katherine could feel everything at once or was it nothing? Time seemed to lose meaning and she could tell that she had no body existing only in her astral body. Through everything she tried searching for her body, her younger body that is but whatever she did she couldn't find it.
In the time she spent searching it could have been seconds or months or even several eternities and she wouldn't know. As she began to lose hope the impossible happened her astral body appeared in a room and before her stood a man.
"Excuse me," she asked with a slight hesitation. "My name is Katherine, do you know where we are?"
"Hello Katherine Pierce my name is The One Above All." The man before her spoke and as he spoke she could tell that he was more than a man. "You are currently in a small pocket universe where you and I shall have a little talk."
Looking around at the room she could see a small window tucked away in the corner and slowly floated towards it and as she looked out she could see a formless white void of nothing.
"You are here because I unfortunately cannot allow you to go back in time and change what has happened to your universe."
"What!" Katherine exclaimed loudly whirling around to once more face the OAA.
"I cannot allow you to change what has happened in your universe because in the year 2023 a year after you conducted your ritual the avengers managed to fix what had happened by travelling back in time using the quantum realm. The reason why you can't change it is because Steve Rogers also known as Captain America decides to return to his time and stay there." As the One Above All explained he looked at her sadly.
"So if this will all be sorted out then what would happen to me? Will you send me back after I did the ritual or something." Katherine asked, feeling a pit form in her stomach as though she already knew what he was going to say.
"I am truly sorry but I cannot do this and there are multiple reasons why beginning with the fact that you just completely separated your soul or astral body from that version of your body. Due to this and because I can't allow you to continue what you were going to do I will give you a choice." As he explains the situation she could feel dread come over her knowing that the options wouldn't be very good.
"The first option you have is to allow me to send you to the afterlife where you will be sent to whatever version of heaven that you believe in," as he spoke Katherine couldn't help but be shocked that it was a lot better than she thought. "The other option is that you will be sent to another universe in a separate multiverse where you shall merge with a different version of yourself. I shall give you some time to think."
Katherine was overwhelmed the options she was given were a lot better than she had thought and as she was trying to decide she had a couple of questions for the man no, the being in front of her. "If I chose the other option where would you send me and would I still be able to use my sorcery?"
"The place I would send you would be a place where you can do some good if that is what you want and I am sure you would and your sorcery may even be slightly easier to use there" after that she nearly instantly made up her mind, she knew what she was going to do.
"Thank you for the first offer but if I can do some good in the other universe then that is where I want to go." As she spoke the words the One Above All smiled at her as though he knew where she wanted to go all along.
"Your welcome my dear and remember excelsior!"
White light again consumed her very being before she came to and before her was her counterpart, instantly knowing what to do she touched her counterpart body and the strange enclosed space she had appeared in faded as the two souls merged.
