I haven't studied Nietzsche, but I don't think Übermensch can be reduced to "take what you want".

It beats the hell out of some stupid formula cartoon that just promotes some equally stupid toy tie in.

It reminds me of this kid.

According to Nietzsche, if I am the Übermensch and you are the Untermensch and you commit an act which injures me, you are acting immorally. However, if I commit the exact same act, but it benefits me, I am acting morally. Any ethicist who says that the morality of an act depends on who the actor is can reasonably be said to be spouting crap.

No moral values apply to the Übermensch. The desires of the Untermenschen mean nothing at all. If the Übermensch wants to murder Untermenschen in job lots, that is just fine. The Nazis put that idea into practice -- leaving murder, torture, looting and general immorality as their legacy. It can certainly be argued that the Nazis misused this idea. However, it is the basis for the train of thought that led to Buchenwald, and Nietzsche cannot be absolved.

The basic problem I have with Nietzsche is that Nietzsche's denial of ethics means that anyone can call himself an Übermensch and "Do what thou wilt shall be the whole of the Law". So there is not just a direct line from Nietzsche to Josef Mengele, but a direct line to Aleister Crowley as well.

Now I have to read the damn thing.

So, you're saying Nietzsche either coined or used the term Untermensch?

I probably should have said "non-Übermensch". It makes no actual difference to my argument.

Can't anyone be an Übermensch simply by electing to follow their own rules?
If so, then who are the "non-Übermensch" to whom Neitzsche was referring?
In other words, who did Neitzsche say was fair game for ubermenschen to prey upon?