Darkness. The otherworldly must behave as their stage prescribes, until the 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 nocturnal: The Sleepless One stays awake while everyone else sleeps, The Midnight Poet turns night into words, and the following stages already work with fear itself.
The method long remained the knowledge of the few: the hierarchs of the churches were in no hurry to reveal it, and many otherworldly ascended blindly, paying for it with their sanity.