The Otherworldly must behave as prescribed by their rank, until the power becomes part of them. Until the potion is digested, the bearer is vulnerable: the power is already there, but they have no control over it yet.
The roles of the Path are service-oriented: the Sheriff maintains order and detains violators, the Investigator gathers evidence and uncovers the truth, the Arbiter passes judgment and bears responsibility for it.
For a long time, the method remained known only to a few: the church hierarchs were in no hurry to reveal it, and many Otherworldly rose blindly, paying for it with their sanity.