"Not to mention in the book the Kan is Kublai instead" That's in the sequel, The Return of the Condor Heroes, which depicts events after the death of Genghis K

"Not to mention in the book the Kan is Kublai instead" That's in the sequel, The Return of the Condor Heroes, which depicts events after the death of Genghis Khan. And since you mention Kublai, Genghis Khan only started the conquest of China. He only managed to conquer West Xia before his death. The rest of the conquest of China was done by his descendants, and so I believe most of the atrocities towards the Chinese occurred then.