I already had a possessed marine with a blue base layer sitting around and I figured id paint him up nice. I decided on a night lords scheme as it would let me practice painting gold, and some lightning effects.
I do get the irony of painting a possessed marine as a Night lord, but he was a spare model I had laying around. I'll probably end up doing some more touch ups and such on him, and he'll be added to my collection of one offs that I do every once and a while. I call them my Rogue Gallery. Eh, I'm a nerd.