Whitelighter
Whitelighters are "guardian angels". They watch over unknown charges and intervene when necessary to help them along their path and keep them safe; they can also be called by their charges. They can constantly hear the lives of their charges in their heads, and if one of them calls their Whitelighter's name, they can usually show up at a moment's notice.
Read more about this topic: List Of Magical Beings In Charmed