You must beat the normal mode using EITHER Sol or Ky. The slight trick is to get the 2nd player to join in while you are fighting someone, beat the 2nd player, and you then get to fight your match against the computer fresh. Getting the 2nd player to join in does not count as using a continue, so you basically get as many chances to beat someone as you need. But you must watch out for being destroyed, since this will force you to use a continue.