those "tablet clouds" look a little bit like they were painted at 100% opacity and 90% flow, using the hard round brush. that's no way to make it work, i can tell you that, tablet or not.
also, they are perfectly aligned, which gives them a very unnatural look. as for the rest, i think its a little flat. tsunade's back is oddly shaded too.
it leaves room for improvement, so give it another go!
