One other reason for calling her a "bride of wire" is for him to feel okay killing her...if he sees her as a monster that harms men by breaking their hearts, he is actually doing the world a favor by making sure she doesn't harm anyone else...he has to justify why it is okay for him to destroy her just like Frankenstein's monster had to be destroyed. She has no heart; she is not really human.
One other reason for calling her a "bride of wire" is for him to feel okay killing her...if he sees her as a monster that harms men by breaking their hearts, he is actually doing the world a favor by making sure she doesn't harm anyone else...he has to justify why it is okay for him to destroy her just like Frankenstein's monster had to be destroyed. She has no heart; she is not really human.