Personally the ideas you have for male and female are very similar so it's probably just better to stick with the male at this point although it's up to you lol
In concerns to feedback, proportion wise your dude's head is far too large, and I think you could push the gesture and silhouette of the character (i.e. bigger shoulders) and the final sketch looks pretty promising so far!
Whoah this is awesome man! Not composition feedback, but the piece would harmonise better if there wasn't so much full saturation in the piece. Perhaps if you toned it down in a way to bring attention to his own saturation it would help. It's pretty but quite hard on the eyes. The way you've painted the body is looking really appealing
I decided to change the composition , in this version the character will be more understandable, also edited the character design itself. Removed the extra armor . Once I do the spirit of fire that huge armor is too much , perhaps will stop there for this version , I will try to work out . At first I didn't really know what I wanted to do for the contest .That's why I have such different sketches. Now I'm more confident about what I want to draw .