These bad boys will be armed with twin-linked devourers - proper dakka fees - and the parts are assembled beside them. I experimented with different patterning techniques on these guys, and I think that it turned out pretty good.
Just for a side project, I've also starting assembling a squad of Black Dragons Space Marines (see my review on the excellent Death of Antagonis).
I highly doubt that I will ever do a full army of these, but they were good fun to assemble - I've used a variety of heads, spikes form various WFB kits, and shoulder pads from Chapterhouse. I just need to find some jump-packs and some time to finish them!