[Ditto]

If we're going to talk sheer numbers, the Mongols probably killed 100M+ in less than a century,

I find that hard to believe. Ya, they killed any one who resisted, but I doubt it was 100 Million.

[Restorer]

Some of the numbers I've seen for the Mongol invasions:

Population of China reduced by half in 50 years, from 100M to 50M.

5M killed in Central Asia.

5M killed in Russia and Eastern Europe.

5 to 7M killed in Persia.

A little known fact: The Mongols for a while had a state policy of killing the entire population of China, with the idea that this would give them a lot more ground to pasture their flocks on. Until a Chinese official pointed out that hard-working Chinese peasants are a much more valuable crop per acre than sheep or horses.