I have recently come up with a theory on the Mysterious Man. Some people believe he is the Vault-tec Rep, but I was looking closer at him. I believe he is Nick Valentine, pre synth. he wears the same clothes and the trench coat is open exactly the same as each other.

Yeah except that the mysterious stranger predates this game by almost 20 years.

But... Valentine (synth) was created with the conciousness of a detective from pre-war.

search Nicks office. something interesting about this topic there

And Valentine is I believe the only companion to notice and talk about the Mysterious Stranger.

Because he's a detective, and there's a psycho going around shooting people. There's a paper in his office. It's just a fun Easter Egg.

This. I was just trying not to give anything away lol

It is a cool and different thought though, I haven't heard of anyone thinking it was Valentine (pre-synth) that was the Stranger.

If you think about it, its a possiblity. Doing Nicks quests, he does tell his synth story of his memories & for some reason when i managed to get a good look at the "mysterious stranger" it does seem to reseamble a pre-war Nick but I do wonder who it is lol

Ya, i don't personally have the perk, but i saw in a video that he has a handlebar moustache. And the fact that him and Valentine wear the EXACT same outfit, makes me think that it is nothing close to a coincidence. The video that shows his face... /watch?v=eUtG_u-MGLo (paste after youtube.com)