Get back up(edit)

Oc takes over Sakura's body at the start of the series.
Major plot destruction when her being there changes her parents fate, leading them to die.

Same team, but with foreknowledge from a completely different world that hosted the 'Fox Boy and Red-Eyed Prince' book series.

****Her original world is similar to the Harry Potterverse, (could be an au of it, except the HP characters and places like Hogwarts don't exist.) except magic is not a secret and their technology is better developed with it.
They also don't need wands, but they do have to perform rituals to a patron deity in order to use their magic each year without it building up and poisoning their cores. They also can have a bond with a familiar, or divine/demonic entity (who has an animal shape) and that partner becomes their sibling, and can enhance their magic/fight together/heal them/ perform differe tasks etc. depending on what they are.