One of my ideas was to do a psychological thriller. It would be like Secret Window, David Koepp (2004) meets Fight Club, David Fincher (1999).
The main character would be a schizophrenic male who would murder people yet not knowing that it was him like in the Secret Window.
My second idea is very much the same to idea 1 but the main character believes he has made a new friend, not realising that the 'friend' is in fact a figment of his imagination due to him being schizophrenic. There was a plot similar to this featured on Hollyoaks.
The scene starts at 1:30 where the character Newt is talking to his other persona Eli. Eli is trying to persuade him to place a bomb.
I wouldn't be featuring a bomb as this would not only be extremely hard and near possible to replicate but it doesn't appeal to me as a storyline.
In my film the main character would go around with his other persona and be persuaded to murder people and maybe eventually himself.