Lilith smiled and spoke in a soft tone, "Firstly. Absolutely never let anyone know about your book. Mortals do not and will not understand but most Celestials or Primogenitors who learn you have one of the [Keys] will come at you with everything they got and will not stop until they die or get the book from you."
She laughed heartily. "You are lucky I am not much interested in power. Otherwise, I would also be tempted to give it a try. That's how lucrative your Key is.
"Secondly, your curse has yet to show its true power. This is a punishment that Cain had never managed to get rid of even after all these millennia and still suffers from it even now. No death, no rest, and not even the right to fall into insanity. Endless and unrestrained agony. For all eternity."