She gets her second chance with "the enemies" still being alive, but its a different body 5 years later. It seems like her first life she practiced martial arts but her focus was being a wife and empress. However, it seems like the direction of her second life will focus on cultivation and martial arts. This is only my assumption based on minor clues given in first 4 chapters and plot summary.
There are not enough women due to their weakness at the beginning of the apocalypse. The writer makes the M/M bonds seem part necessity and part desire.
She STILL has not restored her core, BUT what makes it fun and exciting is that she is still OP and a complete BA little girl!
It might just be me but when I originally read the summary I thought the story started with him already in a relationship with ML which made me hesitant to start reading due to preference. The story starts at a broken relationship and then the development of a career and new relationship.