I like the idea and the expression on the character. One thing to think about is how the clothes would rest on the characters body. Right now they do not seem defined. Are they supposed to be form fitting. Good way to get that in is reading up on cloth or drawing from life. Observing people as you travel.
I registered just because I think I saw what is wrong with the character.
You are speaking of the one in the front right? If so, then it is a question of perspective. The three quarter you made is somewhat wrong. The right shoulder should be a bit more back. Think of it in terms of relations from the head to the torso. if the head is one way, and you want it all to go the same direction, then you should follow perspective and add it to your drawing.
It isn't wrong, just slightly off. Best way to know for sure would be to flip your image. That way the mistakes are more noticeable because you see them under a fresh perspective.
On the character in the background, it is more a question of proportions. At the moment it is 5 heads and a half. The most common proportions for characters is 7 heads and a half.
Personally, I think you went a bit far with inking. There are parts of the body on either of those drawings that become lost because of how dark you went on them, such as the chin and the neck.