Cleanse Land: Lv. 100 druid spell; 5m cast time
This spell, cast by druid or possibly dragon (druid makes most sense) would clense blight off an area of land. Of course, it would aggro any blight mobs within a large area. They already have the simulation for a creature to "blight" land where it walks, how hard must it be for them to "unblight" it?
Use this in combination with the walking blight effect, and it could seem like a constant battle to maintain the absence of blight.
Groups could work together to defend the druid as he casts the spell which would have like a five minute casting time. This allows there to be a battle over whether he gets it cast or not (Possibly even have the spell trigger a local spawn of local mobs) Would make the game more interractive, and actually interresting as players try to work together to clear out blighted lands.
Just an Idea;
Whaddya Think?