It's well known that Asimov modelled his Foundation series on the Rise and then Fall of the Roman Empire. One of the key villains in the later volumes of the Foundation series is the Mule, a mutant that can not only read human minds but also reset them by manipulating their minds as though they had 'dials on them.' I don't recall there being any particular redeeming virtues about this character. He seemed to be purely motivated by the accumulation of power for powers sake. By resetting their minds he possessed them, in a sense, stealing their souls. The worst thing of course they weren't even aware of it. But we of course, as readers are.
Did Asimov have any character, real or literary in mind, when he thought this character up?
The word mule itself means a kind of mutant, a sterile cross between a male donkey and a female horse and in general, is not seen as a term of approval or approbation in anyway. But I'm looking for more in-depth analysis of this character and its antecedents.