Wraeththu, by Storm Constantine

After a nuclear/biological holocaust humanity has to live side by side with another sentient species derived from itself called Wraeththu. They are passionate beings with strange magical or psychic powers and they are fast obliterating the humans either by death or by converting them to their numbers (what is done by an injection of wreaththu blood). But that only works on males... and the Wraeththu are hermaprodites... Awesome reading and probably the kind of material any goth or romantic would fall in love with. By the way, Storm Constantine has some music connections in the goth scene and had Valor, of Christian Death, write little poems for each chapter in the second book of the trilogy. Read them listening to "The Wind Kissed Pictures", by Christian Death.