City Buster

Block Buster: The definition here is that they could basically leave a whole city block in ruins, probably knocking down some buildings, on their own without relying on external weapons.

City Buster: A Block Buster could maybe destroy block after block, but under normal circumstances they'd wear out or it would take so long that they'd be stopped well before it got to that. A City Buster, on the other hand, has the power to destroy a whole major city and could get it done fast enough or have the defensive capabilities to accomplish such destruction most of the time. They would not have the energy projection or speed to be a planetary threat however.

Nation Buster: Characters who can take on a whole Nation.