Cool idea. I will be posting the last chapter of my 3rd novel on Steemit on Tuesday (it's the third novel I've written, out of four completed novels, but the first I've posted on Steemit....I've published the others on Amazon). I don't know if I could turn over my characters to other people like that. I'm too attached to them. Unless, of course, it was for a TV or movie deal, and then I'd be happy to let others write for them. :)

Good luck with your contest. It's a really unique idea.