A dissociative identity disorder sufferer starts hunting a clandestine agency who, he believes, have artificially created his condition to hide a ruthless assassin within his own mind.
This logline is a very complicated read the plot is difficult to discern and not limitedly clear.
The MC is secretive and a former marine and has a “…dissociative identity disorder…” and has an “…alter ego who’s beginning to fight for control of his body.” This is just too much for a logline.
The fact that he takes his own family hostage is confusing how will this “…expose a clandestine agency…”?
Why would he take his own family hostage if he only believes that the bad guys are trying to do something bad? to take such an extreme action that will risk audience empathy he would have to know for fact that the the bad guys are up to no good and this will beyond a doubt be the only way to stop them.
I like the idea of a MC having a split personality and a ruthless killer inside him or her as a result but this logline simply doesn’t convey a plausible clear scenario and a relatable character.
Also what is the inciting incident? Why must he now take such an extreme action? After he takes his family hostage then what? What will he do for the rest of the film? What is his goal specifically? How will he know his attempts were successful at exposing the agency? What will his success look like?
Hope this helps.