Been and voted.
Oh, I don't think you need to worry, it's a good first submission. Very nurgley. I would like to see a close up of the side of the head and the DP's back, if possible.
The hard part with Nurgle and Orcs/Orks is it's really hard to know how it will paint up but the head is always a focal point so some extra detail/care there should pay off. You could angle the head to follow where the gun is shooting (left), maybe add some ridges between the eye sections (define those segments, don't need eyelashes and lids but some flesh/armour between might be cool) or add some crevices (define them, making them look like a soccer ball).
Did you add the chaos symbols on the left arm and/or the chest? They might could use ... something. Maybe cracks, gouges, radiating fractures (as if Nurgle whipped out his pocket knife and cut up the prince when he recruited/promoted him) or ridges and torn outward/smashed inward armour panels or some leaking blood and guts...tendrils etc. There's lots going on so leaving it simple/subtle, less complicated, probably not a bad thing, if that's the intention.
These are all more options instead of improvements I'm suggesting. Best of luck.
