Sam in the cage - sketch - ideas please?

[amberdreams]

So I had this idea for a picture - Sam huddled in a corner of the cage with Lucifer and Michael - and so I did this pencil sketch. But now I'm not sure what to do with it next. I'd had a vague thought about making it quite dark, maybe with shadows of wings falling over him, but I don't know...

If anyone has any ideas, I'm open to suggestions! Of course I don't know whether I'd be competent enough to fulfill them, but throw them in any way.