Your modeling is excellent. The way you posed really conveyed the seriousness (I take it that serious IS how you wanted to come across...) of the situation. Your expression is fair, although try narrowing your eyes slightly. When I put on a pose, I try to imagine how the I should be feeling (happy, sad, enraged, violent, etc.) and think about something that makes me feel that way. For example, when I need to feel scared, I imagine myself taking my biology midterm. When I need to feel happy, I imagine how it will feel when I finish my midterms. It's easier to put yourself into a relatable situation that makes you feel similar to your character, than to put yourself in a character's exact situation. Also, try taking the picture from a more front- facing angle. This is a brilliant cosplay.