Nazgul and Blue Wizards

Now here is the thought: why not get a few good ideas together about some 'neglected' LOTR plots, eg. Black Riders origin, Blue Wizards etc. and collectively commit to deliver a top class fan art. What mischief has Saruman done to the blue Istari so that they stayed in the East? Who were Nazgul originally and how Sauron ensnared them when they were still Numenoreans? What did Queen Beruthiel's cats have to do with it? Good ideas&feedback much appreciated :)