Looking for a book with the same plot at the anime 7th time loop

Hi Reddit,

So I just finished the anime 7th time loop and I can’t stop wondering if there is a Romantasy book with the same plot points.
-Girl gets reincarnated after being killed in a war each time, living multiple different lives.
-The male love interest is dark, moody, and mysterious.

Ideally it would be a romantasy book that isn’t YA but instead for adults (aka a little spice).

Thank you!!