enigma:
(plural: ‘enigmas‘; pronunciation: the letter ‘g’ is said with a ‘g’ sound as in “gun”)
a person (also a thing or event) that is very hard to understand,

Christopher Hitchens, a political enigma
Hutchison feels that his new secretary is an enigma because he’s not understood anything about him — how his mind works when he’s given any difficult task.
When the news reporter could not find anything sensational about the young politician, she called him an enigma to create a kind of curiosity in the general public!
Most of the spiritual leaders like to be called enigmas for one reason or the other; some may be criminals in their past and some others may believe that when their followers know more and more about them, they may lose interest in their god-men!
