ProfFandango posted...****POSSIBLE SPOILERS*******
Once you beat the game you can unlock the Dastardly Bombers to play as in Battle Mode (AND Story Mode!)
By pressing the B button you can use their signature bombs! This works in local multiplayer and Story Mode, but I haven't tested it online yet (I only have Magnet Bomber so far because they're really expensive.)
It does, but only in free play if they have the option for special abilities turned on. Ranked battles however, no specials. With Karaoke bomber, her heart shaped bombs seem to be like proximity mines, they blow up when another player is nearby, but I end up killing myself more often with it because I layed one near me and another opponent.