Aw, bless you!! You are super talented and I'm sure you're going to do something amazing.

I've never done this particular challenge, but when I did the general SPN reverse bang, the art was posted anonymously by the mods in a big post, and then the writers claimed whichever one that they come up with a good idea to write for. I don't know for sure, but I imagine this one will be similar. So whoever chooses yours it'll be because they want to write for it!