The Otherworldly must behave as his stage prescribes, until the power becomes part of himself. Until the potion is digested, the bearer is vulnerable: the power is already there, but there is no authority over it yet.
The roles of the path require working with facts: the Reader collects what has been read, the Detective conducts investigations and untangles others' lies, the Erudite and the Prophet move from collected information to conclusions that no one has yet drawn.
The method remained known to few for a long time: the hierarchies of churches were in no hurry to reveal it, and many Otherworldly rose blindly, paying for it with their sanity.