This is cool, but doesn't he have a more circular helmet? maybe if u make a bust of his head and shoulders, maybe these tips will help, try to use a few bohrok sheilds and the turbine plates of the jetrax (for the head), though the plates are black i painted the whole thing, Yeah i cheated, sort of but honestly, it is hard getting black bohrok shields, maybe use the same pieces of the toes of the front feet of my Manos character, If u r confused have a look. they r also the small blades on the shoulders of arby, not the ones that go on his body(If u want u do this, i'd love to see what u come up with)
One thing i see right away is that the legs are a bit to short and thin. also, it would be nice to see a different helmet, one that wraps more around his head. hmm, after seeing this, i think i may have to try my hand on my own arbiter moc sometime soon.