It's a good piece, but two things stand out in my mind that could really push this piece forward. First, on his face you've applied the deep shadows and a highlight, but you need some medium shadows (burnt sienna/dark flesh + fleshtone) to ease the transition from the burnt umber-ish shadows to the very light skin tone. Second, on the armor and metallics a much brighter highlight applied to the very edges would do wonders in creating that high-contrast edge-highlighted look all the crazy kids are into these days. Good work and I look forward to seeing more from you in the future.