[She balks to discuss it with another magic user- with anyone potentially intelligent enough to figure out the formula, but... If she spoke about it in the vague terms she'd learned of it first herself, the same she'd been willing to give her visitors... That would be fine. (Right?)]

Is is a spell capable of creating the miasma werewolves and other creatures require to survive in a world encroached upon by humans. The ultimate magic my ancestors all strived to perfect.

[And Gilgamesh, well. There were untold magical times accessible through that Gate.]