Though, I think Neitzche wanted the lack of god to be replaced with humanity striving to build themselves into the ideal species. I'm sure eugenics was born in that thought space. Not what I think he was going for, but his sister was a real piece of work and decided the Nazis would benefit immensely from a cruelly twisted and completely misunderstood philosophical thought process. If she hadn't misinterpreted his thoughts regarding the Ubermensch deliberately, who knows what could have been different.