Nietzsche preached the ubermensch, the man who overcomes nihilism, and re-evaluates or creates new rules, while rejecting old societal ideals and moral codes, all through his will to power.
The Nazis loved this stuff, even though Nietzsche did not believe there was any such thing as a living ubermensch, and that the ubermensch was not something biological, i.e., not the next step in evolution, but rather a state of mind, a temporary state of the will to power that rejects nihilism. He believed in the superiority of certain races, to be sure, but also believed that anyone could theoretically be an ubermensch.
Even a Jew. Nietzsche was not antisemitic, and when his sister married one, he broke off with her, as he had with composer Richard Wagner over Wagner's antisemitism.
And Nietzsche had no use for the self-sacrificing, Jesus Christ; the ubermensch, through his will, would break free of God-centered consciousness.
No matter. Hitler found what he wanted. Germans = ubermenschen. And he found justification for genocide in the New Testament. And if there had been no New Testament, and no Nietzsche, he would have found justification for his crimes elsewhere.
To the wicked, everything is pretext.