When an angel is tasked with showing a suicidal woman what the world would be like if she had never been born, he struggles to find a reason for her to live when they discovers it would be a vvastly better wold without her.
I think this is a very interesting idea. But I am not sure who is the protagonist, the angel or the suicidal women.
I think it would make for a stronger, more compelling story if she is the clearly designated protagonist, that the negative verdict from the angel paradoxically and perversely gives her a reason to live, an objective go: to prove him wrong.
It seems to me that however the story is cast in terms of who is the protagonist, ultimately the woman must become proactive, become the agent of her own existential salvage operation, her own redemption.
This a gem of a concept — but I think it needs some cutting and polishing to make it a sparkling jewel of a script.
Go watch the director’s version of “the butterfly effect”. It has the same sort of theme, the world is better off without the person. I think your theme is good. Especially the realisation of the Angel. It would challenge all the Angel’s belief systems. How can all life be sacred when the world is better by the death of one person.
Now for the logline. Take out worlds until it stops making sense. “An Angel shows a suicidal woman…” for example. If the Angel talks to the woman, the Angel must have been tasked at some time. Focus on the story’s main purpose, you have a good one.