That's a tall order. In terms of the villain sprites, are we talking a complete set of sprites with a variety of moves, like enough for a BOR character, or just single sprites?
If there are a lot of sprites for each character, I can do it, but it won't be any time soon. I have a lot of other time commitments, which is why I haven't been doing any covers lately. I'd definitely need the villains from the first half of the list, up to Thor in Asgard. If time isn't an issue, though, I'm up for it. If you have backgrounds in mind, let me know what they are.
Also, do you have any other villain character sprite sets available?