The Otherworldly must behave as prescribed by their rank until power becomes part of them. Until the potion is digested, the bearer is vulnerable: the power is already there, but there is no control over it yet.
The roles of the path are service ones: the Sheriff maintains order and detains violators, the Investigator conducts inquiries and extracts the truth, the Judge passes judgment and is responsible for it.
The method remained the knowledge of a few for a long time: the hierarchy of churches was in no hurry to reveal it, and many Otherworldly rose blindly, paying for it with their sanity.