An idea for DLC, or failing that a mod (though I utterly lack the skills to work this).
While a historical sim is great, and it caught my attention to back, my first love in gaming is fantasy. In this case I am not after orcs and elves but mythical age elements, active roles of pantheons, champions of the gods, monsters etc.
I would love to spice up my city manager by having to curry favour with active deities, recruit mythic heroes to fight other foreign heroes and monsters etc.