I'f i were god.... I probably would let nature run its course BUT I'f i saw people massively killing people sort of like Hitler did I would of course have to end there kill streak (no pun intended).
If you abuse a dog you will condition it to bite strangers. This is not because the dog has an inherent disposition to bite people, it is because the conditioning it has received prompts it constantly to do so.
As I said earlier, physically, literally, neuro-scientifically, power is a drug. When you think of power, think of injections of heroin + speed + ecstasy + alcohol speedballed into the pleasure centers of the brain. Ever heard the expression 'drunk on power'? It's not just a figure of speech.
As soon as a system or structure of power over others is created, you will create an equivalent amount of corruption, as certainly as night follows day. It is not anyone's fault, it is just how man is. Therefore, the only way not to have corruption is to not have a system of authority. Hence anarcho-capitalism / voluntaryism.
This nature IIRC stems from the override capacity of old reptilian brain. Humans have essentially two brains in the skull, the old animal brain which deals with all the direct physical stuff: fight or flight, sex, food, sleeping, pleasure, and the rational brain which deals with cognition general. When given the chance or brought to the opportunity, the old brain will completely override the thought centers of the new brain. Humans have no choice about it -- and you will see it if you ever see someone do something stupid in a panic, like throwing water on an oil fire. The only way to avoid the activation of the old reptilian brain is to avoid situations which we know will activate it.
I'm no neuroscientist, but you can find more info here:
http://en.wikipedia.org/wiki/Reptilian_Brain
http://en.wikipedia.org/wiki/Amygdala_hijack
And here:
http://www.freedomainradio.com/Videos/FreedomainRadioTheBombintheBrain.aspx
The hypothetical is actually not worth exploring. Power corrupts and absolute power corrupts absolutely. If you produce an absolute power hypothetical, then you just reproduce the Stanford prison experiment, but 100,000 times worse. Power is a drug, it takes over the personality and short circuits empathy and reason in the human psyche. This is not a guess, it has been proven over and over again in behavioral studies.

