Here's an idea for an event. The Blight Storm. This storm would sweep from the Eastern Blight to the west, meandering as it goes. In the center of the storm (causing it) would be a Blight Elemental (Think of a giant whirlwind of green and black) that would have massive health, do AoE blight damage for it's normal attack, and regenerate.
Once the Blight Elemental is destroyed, the storm would dissipate.
Effects of the Storm: Any resource it hits becomes blighted resource. Any resource creature (wisp, sheep, cows, etc.) become Enraged (increased level, hp, and attack based on the Tier of resource) While in the midst of the storm, random lightning bolts strike out and have a possiblility of striking players doing ltng. damage to them.
Just a thought,
Whaddya Think?