Before I start I warn that this isn't a suggestion for now but set in place for much further down the road.
Throughout history the right of kings has often been considered to be mandated by the gods itself or in some cases the king has been a god or demigod (sometimes of virtue of being a king rather then being related to a god)
Thus I think it would be an interesting idea if, when gods are finally real, for such to occur in game. Instead of gods chosing heros to represent them they could lean towards the royalty and take a more active role in politics and how it is carried out. The gods could even chose that the king of a kingdom could always be bestowed with godship, or similar, in order to rule the land.
The death of a king, by causes such as murder, could cause other effects. In shakespear plays this is often represented by nature itself going crazy such as sheep eating wolves or something along those lines.
Gods could also have servants specifically set to guide rulers under their influence.
Of course this isn't to say that this couldn't happen even without the god's concent. Perhaps they believe the king is a god or the king is always chosen by the gods even if the god has done no such thing. Fake sons and daughters of the gods, as common in history, could be created with people claiming to be demi-gods or have sons or daughters of the demigods.
Just some food for thought. What do you think? What could be added? what should be taken away?