Thanks Sadayo. I had researched this before I came up with my word mystagogue.
Agogos is an Ancient Greek word meaning 'guide', so, as you imply, a mystagogue might be an energy which steers our lives at certain crisis points through the medium of mystery, or it might derive from the 'ether' of mystery. My footings are weak here but I have a feeling I'm writing towards something significant . . . well to me anyway.