Different system, but I designed a mad-scientist type hero for Champions whose primary weapon was a backpack meson gun. It was extremely powerful, but took a turn to warm up, and then was very hard to aim. You'd hear a loud rising whine, and then somewhere nearby, often in more or less the general area intended, and disregarding all walls/armor/whatever, there would be an enormous explosion. It was fun to start the firing sequence and watch both friends and enemies diving for cover. :)