This isn't my story creds to kyaru-chan on FanFiction.Net They haven't updated the story since 2011 so feel free to continue it

Eulalia O Fontaine had been plagued with misfortune since the day she was born. Being the first ever Shadow Witch in her long family line of Light Practitioning Mages, her life has always had an abundance of unrest and everything nefarious. Considering her reputation for attracting trouble, it was no surprise when the class golden-boy accidentally involved her in his own troubles with the wicked. Somebody was releasing Hell demons into her school, and of course, she found herself plagued with the problem of stopping them. With the help of her natural enemy, Eulalia finds herself in a race against time. While trying to outsmart fate itself, in order to keep her world safe from dark powers, Eulalia is faced with the realization that her life will never be the same again.

When Lexa dies, Clarke climbs to the top of the tower and is struck by lightning and sent back in time to the dropship landing. Here, she retains all her memories and has to fight to right the wrongs of the future, and find her way back to Lexa, the love of her life. This is fiona_249's story from ao3 #1 in eliza 12/05/20 #1 in girlxgirl 27/08/21 #1 in lexa 13/07/21 #4 in the100 24/06/21 #1 in clarkegriffin 11/04/23