I agree. I think China could be a prime candidate for a future Empire that will act without mercy and pity. You noted that Afghans might have buddhist genes in them. That is true. But like Christianity, Islam is more focused around culture and belief than race. After all there are African Muslims, Middle eastern muslims, European Muslims, Asiatic Muslims... There is still racism in islamic countries, of course. But their main concern is belief. And even if islam is not uniform and suffers from infighting, their culture is very distinct from say, buddhism. As such, they absolutely succeeded in erradicating the original cultures. Based on what I've heard, China is more racial. Allegedly you have a hard time unless you are han-chinese. I don't know to what extend that is true, because if you read our media you'd sometimes think we never abolished slavery. But I do know that China is much less racially diverse.