After about five hours of attempting and erasing, I've determined that I need some help. On two things.
First, this is the best I've managed to get their arms. It doesn't look right to me, but by this point I've been staring at it so long that I have no idea how to fix them and still keep the same basic positioning (I know it isn't comfortable for arms to be twisted that way, but I need Tera's wrist out so her scars are visible).
Second thing is that Tera's angel (the boy with the blindfold) needs a wing. He only has his right wing, but I'm need it curved around him on the far side since there is going to be something behind/between them that needs to stay visible.
O.o The wing I've been trying to find reference pictures for (my other attempts were too obviously wrong to even bother uploading him with) but any suggestions or advice would be really helpful.
And any critique on the rest of the picture would be really helpful as well, since I'm still working on drawing this and trying to get it right, so I'll be able to make changes pretty well right now.
Edit: Managed to get it quite a bit better with Asbeel's advice. Still not sure about his wing, and I'm still working on it so advice is still

^^
Comments
Asbeel Says:
Loverly concept!
I think the reason you're having trouble with the arms is actually because of the chests. Let's see if this will help:
[img=http://userpages.prexar.com/artemis/fortai.jpg]
The angle you're depicting the arms really need to show the shoulders, and in order to do that, you'll need to show a little more collarbone and thus widen the top of the chest. I think once you work on that, the arms will fall into place. Also, the hands need to be a bit bigger, giving more substance.
I doodled the wing as I interpreted your description; one question about his missing left wing: how is it gone? If it was surgically removed, or chopped off (like my character Asbeel's upper left wing) or is it just missing?
Anywho, I love their faces! Excellent design work here!
Asbeel Says:
Oh, yes -- much better! ^____^

The wing's position is very nice -- I can't see any way to improve it. Wings can be stylised, too -- though I might slope the feathers inward a little more to create a more natural curve. Otherwise, you've got a great thing here!