GOOD: Mahatma Gandhi had a great reputation for being India’s de-facto leader and a non-violence preacher.
BAD: Hitler too had a great reputation but for being notoriously evil.
BOTH: But Rasputin, One of the most powerful man of Russia during the First World War, had a reputation for being a mystic healer. But he also enjoyed a reputation for being a love machine which was hated by many
LIES: Genghis Khan, the Great Mongolian leader; he had a great reputation of being brutal, blood thirsty and has killed many people in his conquests. But many times questions have raised among historians about was he really a tyrant or he publicized himself to be that way because he wanted to instil fear in the minds of his enemies and get them to surrender even before he attacked?.
Moral of the Story: Whenever we listen to the word reputation, it does not mean, it is always good or bad. It is only the perspective of the person on the other. What might be good for one group, might be bad for others.
Reputation is for characteristics of the person and not the person as whole. Hence a person could have a reputation for a various reasons and not just one. Only the prominent ones or the extreme ones (specially the bad ones) will get exposed.
Sometimes reputation may be built on lies. The person might not have those qualities and might have been made up by others. But the reason why the reputation might have survived is because of the consistency.