Name: Dense Fog
Circles: Air / Protection
Description: All ranged units cannot attack more than at a very short range (adjacent units or maybe one cell more).
Notes: the "still can attack adjacent units" is to allow them to still target flying units, else Draconian + Dense Fog would be OP.

I like it.

Aaron, I'm hereby proposing that ranged units be able to shoot adjacent flying units without any engagement penalty no matter what. (Engagement penalty still applies to walking enemies.)