(Modern setting) FL was murdered by her husband as she was confronting him cheating on her with her, then best friend, while she was already dying from end-stage cancer (expectant to die within 6 months), and was sent back 10 years.
1000/10
It's not a typical reincarnation story; the FL and ML happen to be the reincarnations of important beings, who look exactly the same way they do. They have the same soul, but they didn't retain the memories from their past lives. Long story short, they were with/in love with each other in their past lives, as well as now--they're soulmates, and reincarnated lovers. However, the story isn't focused on them being reincarnations--that is something you find out later.
ML is the regressor (he was in love with the FL in his past life too, and when he came back in time and killed all those fellow cadets, it was all for her; they were behind her being falsely accused of treason and being executed, so he simply took them out so that wouldn't happen again; it was all to save her)
Endless reincarnations (Sylvia will never stop being reincarnated.)
Father, I don't Want this Marriage