I would say Ni is the most mysterious function (hey, even I don't really understand it). Therefore the most mysterious type probably has dominant Ni, or at the least auxiliary Ni. My guess is that the most mysterious type is INFJ, though "mysteriousness" can take different forms, so this question might be doomed from the beginning.
Is there anyone here who here who is drawn to mysteries, enigmas, and puzzles? Likewise, are you fascinated by people (real and fictional) who somehow seem to possess an "aura" of mystery about them? I certainly love a good mystery.
Which M-B type do you think is the most "mysterious"?
A sub-question: of the two INFs, which is more mysterious? INFJ or INFP?
I don't think I'm really mysterious myself, I'm just quiet sometimes and dont open up easily.
I've always found the ISFP to be mysterious, and introvert intuitive feelers anyhow, cos they have dreams... I've been with an INFP though a long time, but she had a realistic Si streak over her that 'earthified' the mystique.
I find the ISFP mysterious cos of their complex intuition, and cos sometimes I can't really figure them out, but not in a 'wtf are you doing' way, more in a 'i can see an emotion/thought in you but its not really clear what it is'.
They always surprise me with something in them I didn't expect or hadn't seen. It's endless.
Heh. Ironically, the OP is very transparent. It would be like an INTP asking what the most linguistically precise type is, or an ISFJ asking which is the most socially conscientious type.
Oh, but I disagree. Mysterious can be quite subjective, no? INFPs will naturally not find themselves or other INFPs who are similar to themselves mysterious. And I can see how introverts can find extroverts to be mysterious. As Jung says, your opposite is the most mysterious to you and often the most fascinating.
I personally find I_TJs to be the most fascinatingly mysterious and E_TJs to be just plain baffling.
I don't really find INTJs to be all that mysterious. I have an INFJ friend who is pretty "all cards on the table-confessional" and yet she still manages to give off a general air of mystery sometimes. Kind of like she has a dark side.