Genghis Khan: was he a crazy murderer?

There is a lot of controversy whether Genghis Khan was a great military leader, or a ruthless murderer. It is justified to say that he was a murderer. He killed many innocent lives,and spared few. It is even said that he killed his half brother because he stole his fish. But even with all this murder, it was to expand his kingdom. In the video we just watched g'day in class, it is said that Khan spared the lives of most of the women and children of the people he conquered. But personally, I don't think that takes away form all the other murders he committed. He also tortured in cruel and unusual ways to show his strength. I think he was crazy, but there must have been some kindness in him, if you can call it that. I say this becuase he was willing to spare the life of his best friend Jamuca. They were basically lovers, but became enemies. But when Jamuca was captured, the only reason Khan killed him was becuase he was asked to by Jamuca. And even then, he did it regretfully. So that small form of compassion shows that he is somewhat human.... Maybe.. All civilizations during that time think of his name, and associated it with fear.