Broadly speaking this book can be called historical essay, and the purpose of it seems to be to invite the reader to correctly understand the way that this person shaped the history of the East and the entire world. One obvious idea that emerges from such a consideration is this: it is simply amazing how much one single human life could change the world forever. Although this book is historical, the philosophical implications of its truth is deeply significant.
For instance, there is the philosophical consideration of fate. Because one human had such an epic influence, the reader might begin to wonder why some people are positioned in such critical moments of history, while the vast majority are not. This doesn't necessarily lead to any specific philosophical conclusions, but the consideration of fate is valuable for different reasons. The historical truth of the matter is that a single person changed the entire course of human history.
Another important quality of these essays is that by understanding Genghis Khan more technically and correctly, a person can see past the mainstream opinion of him. The book notices that in the mainstream, Khan is typically depicted as a villain or a monster, but in reality, he can be understood as a single participant in a broad human game with countless other people who would have done the same thing if given the opportunity. By resisting the tendency to demonize him for his power, a person can begin to see that they share a nature with Genghis Khan. Perhaps each person has a similar potential to Khan.