Dragonman_FLying Power Punch: Work in progress. Need your opinion.

I have been working on the poster of my indie comic book project called Dragonman. I am on inking stage of this art piece, specifically on the shading stage. I am looking for your opinions and critiques to make this piece look better and more professional and physically accurate and realistic. Any tips to make my art piece look eye-catching? Please let me know how I can improve this piece?