I am currently preparing a setting that I wanted to be an espionage/investigation style game. Originally I had planned on doing a demon game, but I have now decided to meld that with mage. Currently I am thinking of setting up a Guardians of the Veil Hierarch to mix and match with maybe a handful of demons in town. As I begin to brainstorm this, what kind of interesting ways do you think mage and demon metaphysics and the setting might mix? I imagine that some infrastructure likely also constitutes Mage Mysteries. Matters of conflicting reality would of course grab a mage's attention. Demons may also deal with infrastructure that relies on abyss entities or alternatively infrastructure that traps or blocks abyss entities. Give me your good ideas for crossover tension!