As a pro sculptor still learning things myself...I can see a lot of lil flubs in the conversion work here,but the idea is cool and I like your effort! :)
Really nice face and good concept. The sword is great too. The rough edges on the putty really hurt though. Looks like the putty was too dry when you worked it. Since you're not sculpting features here, you could try sanding it down once it's hardened to get rid of the cracks.