guardian angel 
noun
A spirit that is thought to watch over and protect a person or place: the soul was accessible to the gaze of your guardian angel figurative he was also deputed to be Dame Edith’s guardian angel...
- His guardian angel must have been watching over him.
- It was as if I had a guardian angel watching over me.
- Well you can find classes on how to talk to your dead pets, how to identify your guardian angel, how to bend spoons…