Amusingly, Persephone fits some of the themes. Sought after by lord of the underworld, ends up becoming mistress/queen of the underworld; Vanessa's story in a nutshell, but that might be too on-point for your taste. Hecate is another interesting option. I've forgotten so many ancient Greek deities.

I would normally look to the more primordial gods, but I'm not sure any of the Titans fit... Damn, why the ancient Greeks gotta have so many gods?