I was looking for something else, and came across the idea of threshold guardians. It’s one of those ideas that first really came into vogue because of Campbell’s “Hero with 1000 faces” book. Basically, the idea is that within a myth or story, the hero reaches a point in the journey where they get put up against a monster or something which guards the passageway to another realm, way of thinking, or something along those lines. It’s a necessary transition point for the hero to pass.

An article about how parents and teachers act as threshold guardians for kids.

A thing about the threshold guardian as an archetype.