Added 4 minutes later
Balrog is very similar to a Dungeon Lord; you can level him up to 7, and Nazgûls to 6. Put them on a horse, repaint a Death Knight, and you'll have a dragon rider that's a bit weaker, but with more health and speed, and better initiative.
Added 4 minutes later
I'm having trouble with the modified models; I'm still just learning the program, and I don't know how to make them move with the added pieces, or where to put the coloring.