Other than what Castonia mention, I think you can also work on the composition and other anatomy parts for the character.
I recommend these things:
Maybe making the legs a bit shorter. Push the hand more forward and even make it bigger for that more epic feel with the fore shorting. The back arm anatomy is almost there. I highly recommend if you have a roommate or family member to take a picture in the same pose to get an more accurate anatomy reference. You can probably play with the cloth as well.
That's it for my feedback.