Far to the north, past the cold, vast plains and tangles ancient forests, past even the brooding Deadfire Mountains, lies a real of ice and bitter cold. Barren and stark, few have ventured in to this icy realm. Hunting here is scarce and the wind seems to howl with the voices of demons. Yet there are rumors of a citadel in the heart of the ice field, rising above the wind-swept whiteness and glittering in the pale sunlight. Some say that the citadel was built of block of ice by giants. Others claim that some wild magic caused the structure to grow from the very ice. Yet others state in low voices that it is not ice that shines so, but a fortress of diamonds, built in ages past to guard the most powerful of magics in the world.
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.