I recently re-watched Coppola's Dracula movie, and the prologue struck me as immensely Sorcerer.  It's setup is a reasonable enough historical scenario, until a badass gets very upset, so he stabs a cross and drinks the blood that flows forth to become a supernatural horror.  This strikes me  as a prime example of a passionate breaking of the rules of the universe.

Also, Demons don't exist in that setting.  There is no real indication that what the Count did has any precedent anywhere ever, or has ever been done since.  Every other vampire ever presented is the Count's creation.  Van Helsing cobbles together some stuff from folklore, but there isn't really the feel that this happens once in a great while and the Count is merely the most recent example.  In the history of the world, only one man has ever done this shit.

Anyway, the whole bit has me thinking about a modern-day setting where the PCs are the only Sorcerers ever.

That's a good point! I can't say I'm a big fan of that particular movie as a whole, but I do believe you've touched upon one of its strengths.

Best, Ron