I've had an interest in Mongols & Huns for a while (as well
as other peoples), but many things I've read have been of a
"tainted" nature. I'm sure he was better than he is often given
credit for, but I'm also sure he had a powerful temper...
otherwise, I doubt his revenge would be as it was.
He was far better than he's been given credit for in the mainstream histories. His temper was legendary as well - though he didn't ever let it be his master. In this case, I really can't say that I wouldn't have done the same in his place, can you? The foreign government of (what appeared to him to be) the Western world kills my representatives that I've chosen to be as palatable as possible, and then kills my dearest friend who I sent as a peaceful envoy. Then they send me his head back in a bag and I'm supposed to kowtow to them? Screw that, I'm going to take apart the world if I have to to get at the people responsible.
I'm pretty sure that's how many people would act, as well.