One point about Babylon the Great is that she was 'drunk with the blood of the saints.....' (Revelation 15:6).
The Papal Inquisition lasted for around 600 years (1203-1808), far, far longer than the horrors of Genghis Khan or Hitler.
Here is an account of an Inquisition Torture Chamber:
'....There were instruments for compressing the fingers until the bones should be squeezed to splinters. There were instruments for probing beneath the finger-nails till an exquisite pain, like a burning fire, would run along the nerves. There were instruments for tearing out the tongue, for scooping out the eyes, for grubbing up the ears. There were bunches of iron cords, with a spiked circle at the end of every whip, for tearing the flesh from the back till bone and sinew were laid bare. There were iron cases for the legs, which were tightened upon the limb placed in them until flesh and bone were reduced to a jelly. There were cradles set full of sharp spikes, in which the victims were rolled from side to side, the wretched occupant being pierced at each movement of the machine with innumerable sharp points. There were iron ladles with long handles, for holding molten lead or boiling pitch to be poured down the throat of the victim, and convert his body into a burning cauldron. There were frames with holes to admit the hands and feet, so contrived that the person put into them had his body bent into unnatural and painful positions and the agony grew greater and greater by moments and yet the man did not die.........' [from Wylie's 'History of Protestantism.' The details apparently come from Roman Catholic inventories]
Hebrews 11:36-38 comes to mind. I will keep an open mind as to whether the Papacy is the whore of Babylon, but it seems like a reasonable candidate to me.