Verse: rewrite the stars
Season 5 canon divergence written and developed with @bunnyblooded - After bonding with her on her death bed Stefan felt guilty about Katherine's death and all the time wasted. He seeks out the help of some powerful witches with the intention to resurrect Katherine.
Not being everyone's favourite person, the cost of rezing her is a lot, to be expected.
In order for the witches to agree, Katherine had to be brought back with no memories of her life before, but instead a fabricated story of a much tamer nature. She would know nothing of vampires, werewolves, or even her own heritage as a traveler witch. She would be living the life of normal unepic proportions.
However that was not the only cost, Stefan had to agree to give up his immortality, and all of his memories as well. Unknowingly agreeing to be a case study for the witches involved. What are they studying? The Doppelganger draw. Can you erase the bond? They tried, and then set them in different areas to see if they would ever be brought together again. Prince and the pauper but make it a love story.
So they bring back Katherine, re-writing her history without taking away any part of it that made her who she was. She was still SA'd at 16, had her baby out of wed lock, her alcoholic abusive father gave the baby up for adoption and sent Katherine away. The exiled doppelganger found herself a few states over where she met her "ex fiancé" a wealthy business type with a lot of power and a lot of reach. She called off the engagement, scared of him and his abusive tenancies, she ran. He tracked her down for years, forcing her to change her name and lay low. From Katerina Petrova, to Katherine Pierce. She currently works as a waitress in a little diner, supporting herself the best she can while battling her ptsd and anxiety.
Stefan a similar mirrored story to his history.
Now the two are left to their own devices, while the witches wait and watch to see if they'll once again be drawn together by fate.