This glitch lets your attacks do more damage. First, go to the Free Battle Menu and choose VS mode. Select any mode you want (team or single) and press SQUARE at the character select screen. Move the handicap all the way in your favor, then do a battle and make sure you can win. At the Rank (or loss) screen, exit to the Free Battle Menu. DO NOT exit to game mode select or you will have to start over. Go to Survival and select whichever mode you're trying to complete. You should notice your attacks doing significantly more damage while the COM's attacks are doing minimal damage.