Doorkeeper

Not to be confused with receptionist, a member that greets new-arrivals in the systemundefined:

A doorkeeper is a headmate that can seal off areas in the innerworld, for example by closing gates or erecting barriers. They also guide other headmates through the headspace to get them to the correct destination. A doorkeeper may or may not be aware of their role, and the may simply pick it up naturally.

Related Terms
This may be considered an overlap between gatekeeper and ferryman.