Detective's Angel | L Lawliet x angel reader

What people don't know is that heaven is very similar to earth - it has its own hierarchy, some angels work to keep the universe running, but most of the angels just continue living their lives in the afterlife.
Y/n works as a detective angel which is not very known job. Just like other detectives she solves cases in heaven, on earth and in hell. Mostly the cases are simple such as finding something lost, then there are harder like catching escaped demons. But this time, she gets assigned to a job nobody has ever worked on. Heaven has noticed a very skillful detective on earth and y/n's task is to keep him alive as long as possible and make him a detective angel in the afterlife.
If only she knew what was going to happen...

Please don't take the heaven and all wrong I just somehow came up with something and went with it :)

Enjoy~