As I've mentioned to you already the head on the nid is just a bit big.. I like that you've tried to do something different with him but I think he would have looked a lot better with the open mouthed Gaunt head.
Have him up in a praying mantis style pose just attatched by 1 toe about the lad on the marine when splat.. Face full of boltershell..
love the cleanliness of the painting on the marine and all round..