The PCs come face to face with the Big Bad in a fine stately home when he or she casts a spell and the suits of armour lining the walls draw their swords and slowly clank to the attack.
At regular intervals, a god takes control of your world's weather. Choose the gods at random each turn of the interval and begin applying their effects subtly. Their power will depend on the strength of those who worship them.
For civilised people, worship of a god actually wanes during that god's month in an effort to reduce their potential destructive effect.