Psycho Therapy: The Shallow Tale of a Writer Who Decided to Write about a Serial Killer (2025, dir Tolga Karaçelik)

A struggling writer (John Magaro) in the midst of a divorce befriends a retired serial killer (Steve Buscemi) who incidentally becomes his marriage counselor by day, and killing counselor for his next book by night.

https://www.themoviedb.org/movie/681434-psycho-therapy-the-shallow-tale-of-a-writer-who-decided-to-write-about-a-serial-killer