The Otherworldly must behave as his stage prescribes, until the power becomes part of him. 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 literal: the Corpse Collector and the Gravedigger are busy with dead bodies, the Spiritual Medium — with conversing with the departed, the Ferryman and the Gatekeeper escort souls further.
The method remained the knowledge of the few for a long time: the church hierarchies were in no hurry to reveal it, and many otherworldly beings rose blindly, paying for it with their sanity.
