Of creatures great and small
The Omen Plague has other names. It is known as The Star Plague and even The Mundane Plague. It is still with us today, now known by the common name of the Shaking Death. To set the stage, the stars were aligned in all the wrong signs. Everyone new something bad was going to happen. When winter set in hard and early, they thought that was it. They were wrong.
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.