Why aren't you drawing a background on these characters? Do you realize what kind of disservice you are doing to your art? You have these wonderful characters you're drawing and you are not even drawing a basic line background.
Dude this is totally unacceptable to me and I cannot believe somebody who draws FREAKING AWESOME. Yeah I said it. YOU ARE A FREAKING AWESOME ARTIST. And you are not even drawing a basic background.
That sucks. Somebody who is as talented as you are should be finishing these drawings. I consider every one of those drawings unfinished, and that sucks. Because I want to see what kind of kick ass world you could create.
You're not drawing to your potential. Finish something.