The visual appeal is there, no doubt about it. nothing like an orange sunset/sunrise, back lighting, and silhouettes. :P although i'm going to consciously leave out my interpretation even though you asked for it... i don't feel like i know enough about bleach (what? yeah, i live under a rock. lol. i just don't ride on the biggest bandwagons of them all) for my interpretation to be of any value. xD;;

with regards to the wall itself, i do have a few comments and critiques.
the clouds look filtered to me and that's a bit of a minus. although perhaps you are trying to take away the stock photo quality of it, painting is the better option. proportionally speaking, those guys are gigantic. o__o even though the buildings are silhouettes and you can't see the exact height of each level, it's still possible to judge that these guys are all several storeys tall. (but it doesn't change the fact that this is a nice concept.)

with the silhouettes...well, usually, they aren't solidly defined black shapes. the light should be able to diffract around the edges. that is, the edges should be brighter/have lower opacity than the main body of silhouette. it's kind of like how the clouds are brighter around the edges. but yeah, showing diffraction would have significantly increased the visual impact of this wall. i regret that i don't have a good example on hand to show you. hang on... ok, with this one, it's not a perfect example for your case, but you can see the effect with the guy's shoulder.

again, nice concept. you've got pretty good "vision" in terms of setting up a scene. just some technical stuff that could be improved upon. sorry for the lengthy ramble and if i come across as too critical or something. xP good work.