I guess its not so simple, Simple, after all.

that Hitler, Stalin and Mao were responsible for more deaths than anyone else in history

According to your statement these three individuals were responsible for more deaths than the combined deaths caused by all other human beings since the creation of the world.

Documentation? Evidence? If its so plain, you should be able to provide it.

HOWEVER, the Terrible Troika is not the point under discussion, despite your dodging & weaving. Your statement was - one more time, since you apparently have difficulty reading- was:

atheists have been responsible for more deaths than anything else in human history.

Look, it's simple, Simple. Either you can substantiate - with evidence, not bombast - that line of absolute bullshit, or you cannot.

By the way YOU named YOURSELF the "Simple Seeker" - & I prefer the original.