Perhaps the blight is coming to Dwilight, which I mean the Zuma will start blighting regions, not just claiming them
Given the way that the Zuma have presented themselves to all the humans, I don't believe that they would be the ones Blighting. In fact, if I remember their lore properly, they did not get along well with their warlike cousins and that's why they left for BT.
Perhaps someone should ASK the Zuma instead of assuming?