The number is arguable. Hitler started a war, so indirectly he caused many more deads.
I also wanted to mention that we underestimate the Russian part in the victory very much. Russia offered many, many more lives than any other country in order to wipe out the fascism and end the war. I'm not deminishing the American input, that started in Normandy, but Russian and American military actions are
at least even.
And if I'm speaking entirely on the true meanings of the systems, what they truly represent:
Communism

>>>>>> Fascism
No?