Mao killed somewhere in the neighborhood of 100 million Chinese during his rule. South Africa has a population of just 44 million. Genocide on that scale is well within Chinese capability
Mao [ca. 60 million dead] has never attempted a 'transculturation' - "transcivilization", rather - but functioned fully within the Chinese civ, as a modern day "Son of heaven", albeit in a rather modern garb. One could argue that transcivilizing the Chinese would have taken not 60 million dead but many more.