Imaginary (Niam, Ziall, Ziam, Larry fanfic)

A lot of people believe when you die you go to heaven, but what if you purposely inflicted your own death? Instead of going straight to heaven Niall became a guardian angel, or ghost, as the mortals call it. He was assigned to be an imaginary friend to Liam, a five year old boy from England whose fate showed that he would take his own life when he was a young adult unless Niall could prevent it. Niall thought he had this mission in the bag. Liam seemed so happy. Surly nothing would change that? That is until Zayn, a demon claiming to know Niall, shows up.