George Bernard Shaw, when translating
Friedrich Nietzsche in 1903, chose to define
übermench as
superman. I suppose that Shaw wanted a word that clearly indicated extraordinary and superior capacity or social status, rather than apply a word that metaphorically describes a relative spatial position. It would be hard to imagine the world ruled by somebody called
Aboveman.
Joe Shuster and Jerry Siegel would later take the Superman label and apply it to a benevolent man who flies around in tights, fighting all sorts of villains, including Nazis who saw themselves as the übermenchen.
The 1925 Nobel prize for literature laurate was happy to associate über with super, but after the defeat of Hitler über gained a more negative - but also more sardonic to the risque point of cool - connotation.