Outbride: Beauty and the Beasts Vol. 4 (manga)

Mashiro is the only one of humankind left and is now expected to produce offspring with her male celestial keepers. Thanks to her human DNA, any children she has with one of her consorts are guaranteed to have extraordinary power that could save their world from the gods of destruction! But with nothing left of the world she remembers, Mashiro battles both desire for familiarity and a desire of another kind.