If I can recommend a few things, one would be to push the "V" shape you have all around the design. Right now the left leg stands out because of the different shape language. You can also paint in the ab area as it seems kinda strange exposed like that in my opinion. To me if breaks the idea that she is confident. Seeing as she is a hero, The "V" can stand for victory. So that can be her theme and/or Logo maybe. With her power being able to break the sound barrier with her punches, maybe you has some sound barrier gloves to control her strength. Or you can keep what you have but maybe whenever she's about to punch, a blue aura glows up her fist.
Besides design, I love the face and the hair works for me. She has this peep to her step feel if that makes sense. Giving her that hero smile will definitely work well. Even though the pose is simple it just works to show her confidence.
Hope this helps and I hope you have time to finish.
Thank you so much for your critics these really help ^^ I'm kind of lost in the design and I'm feeling like "I had to choose fantasy theme !" but I don't think I have time to change the idea; I will push the "V" shape more and work further on her gloves... I should also finish the illustration, let's hope I can make it in 1 week ! ( or hoping that the deadline will be extended by 1 week)
The deadline has been pushed to the 13th so you have 16 days I believe. Anyway glad I could help. Hope I didn't sound harsh.
These are great news ^^ I have time for the illustration then. And no worries your comment didn't sound harsh at all, it was very helpful ^^ The reason why I'm participating in here is to get better
Thought about creating a 3/4 view portrait of my character since I want to show the design of the headphones , it is a bit hard to show it from front view. I didn't know that re-creating from a different angle was challenging xD I should do this more often.
Anyway I tried some hair/eyes color variations for fun, I'm thinking about using a.i.
Really like B1 & D2 too ^^
Thank you ^^ I liked B1 as well but I'm not sure it will work with the armor, anyway I will try many variations ^^
Or...you could put oranges on the armor instead of blue for keeping a bound/link/harmonization ? ^^ (if you try with red hair, I mean)
that could be a good idea to use a color else than blue for her armor, so I could use the blue to show the power effects
Oh yes !
That really could be a great idea as well ^^
I like B2 as well.
12 days later
Pink hair is always the best xD
Damned redhead. Toutydroid, you were the chosen one. The hair should have been pink!!!
@innocent Haha, maybe for next year I will make a hero with pink hair ! xD
The illustration is far from being done because I started it 1 day before the deadline xD I had to submit it though on time... Meanwhile I'm still polishing it and I might change few things too ^^
Here is a slight progress for the illustration
21 days later
Updated Concept Sheet 
Changed the background for the illustration and refined the character, I will work on light and shadows 
