satan is behind both sides of the equation.

the objective is mass slaughter, in order to break open a prison and let the locked up demons roam the earth causing even more pain and death and panic.

the angels are standing by and will move to evacuate, and have long planned this and are guiding a lot of big rocks on their way to make sure that, unlike the great flood, the whole of the seed of chronus/saturn is eradicated.

all of this is a lot more mundane than it sounds or looks. probably the book of mormon has a fair bit of it right, for example.