As population increases, animal souls are promoted to human before they are spiritually advanced enough in terms of impulse control, etc.: this shouldn't have happened, but karmic progression is automatic, after all--it's a force of nature. But the 'animalization' of humankind bodes ill for civilization.
No doubt the same goes for elves, dwarves, and so on.
The devil's wind. Explains why people become crazy. They are caught up in this wind which steals their sanity which in turn feeds the wind. The wind is a leftover from when the air elementals banded together in a mass army at one point to attack the True Gods. The wind is leftover of their attack route and on the anniversary of the battle the wind sweeps through causing the madness.