The Dark Night of the Soul is the part of the story where the hero believes all is lost. Every attempt to succeed thwarted and every resource spent. There is no turning back because even the path back to safety is blocked. It’s all over for the hero and by extension, us.
A mentor does many things, but there is one part distinct to mentors; relating experience. Teachers train us in a given discipline. Parents guide us in ethics and morality. A mentor is a guide on the path we’ve chosen.