A self confident hitman relives along a nightmarish night the killing of his last victim.

Story is conflict, and conflict from a story standpoint is what is standing between the lead character accomplishing his or her goal. Since your logline doesn't tell us what the lead character's goal is, we, the reader, do not know what the conflict is, which means we do not know what the story is about.

Lead character: Self-confident hitman

Goal: No idea

Conflict: Since I don't know what the leads goal is, I don't know what is standing in the way of the lead achieving his goal.

Goal and Conflict are important parts of a logline and you should consider adding it to your logline in order to draw in the reader.

Hello FFF,

I thought that ?-"reality" - ?would means something more subjective than -?reality - mostly if placed after - nightmarish?- . However, ?"reality" is not in the logline.

I don't understand ?why you "don?t understand what you mean by ?relives?", as you give the best definition of this:??To undergo or experience again, especially in the imagination?. I thought this were clear enough.

Who's the antagonist? maybe himself, maybe the story ("the plot is a conspiracy against the hero"), maybe something else...