Okay, lets not start throwing around INTJ jabs here...
It would seem that he is schizo. He is at the right age for a young man to be clinically diagnosed with schizophrenia. Men are susceptible between the ages of 19 to about 26 for a diagnosis of this mental illness. When someone starts to feel, see, and hear things that aren't "sane/normal" they litterally don't understand that something is wrong with them.
I helped someone who had a mental problem like this and the doctor asked him--"you know how you dream at night but that isn't real?" They said "yes". The doctor said, "well sometimes your mind can fool you while you are awake like in a dream. So can you believe that those voices you are hearing aren't real?" The person looked at the doctor and thought about what he said and replied "No, the voices are real".
From what I have read, it sounds like this guy went down the path of schizo and didn't get the medication and help he needed to stop his dangerous fantasies or whatever.