i think it is like this. greatness can come in any form. just look at einstein or alfred nobel. Their discoveries and invention gave a new definition to the science and daily lives of human beings. but the same discovery and invention has brough terror. So, we need to see the greatness in two different aspect. Someone who is great is not necessarily good. They might be evil. Such as Ravan was a great king and so were Nepolean and Hitler, but they were all evil. We also have Buddha and Edison who are great but good at the same time. I think Prachanda is a terrible person, but without doubt a great mind, whose counterpart is a genious Baburam.