Would it make sense for another entity to "rebel" against the Raven Queen and come to the Material Plane to try to conquer parts of it to have its own dominion? Thinking something like the soil spirit The Dearth from Leven Thumps and the Gateway to Foo for an idea. I just don't know why someone would do this necessarily. Or basically, just in general, what goals/reasons would entities from the Shadowfell have, to try to conquer parts of the Material Plane?