There is nothing so pure until 100% in historic characters. 曹操老贼 is 曹操老贼 however. The historic character of bastard Cao Cao is something that we will use to teach future people - our grand children to differentiate between GOOD RIGHTEOUS POLITICIANS and BASTARD POLITICIANS. The status of Cao Cao is a NEGATIVE ROLE MODEL. That is his value in history. He is a poet, writer, Prime Minister, ruler, warrior, cunning ruthless, selfish bastard.