I loved avatar as much as anyone, and will join. I always had kind of a fanon explanation about why the magma bender would see fit to erupt four volcanoes at once. If some army was marching through in a war, or maybe the very start of a war, the magma bender would try to stop them. The general might say that even if he defeats a hundred, or a thousand men, it would be a mere drop in the bucket. So he demonstrates an incredible power to show he really can defeat an entire army by himself.
Well, aside from my rambling, I'll join. Are there going to be limits to what we can get away with? Given some of the more rare abilities benders can possess. I'll take air, but they're all cool so I don't really mind which I go with.