Successfully complete the listed task in Stage 7 with the indicated faction to 
unlock their Last Gaiden stage:

  Sengoku: Get 1,000 KOs.
  Shu: Escape from the burning castle in less than two minutes (all friendly 
  officers as well).
  Wei: Defeat the defected Da Ji in less than one minute.
  Wu: Rescue the Sun family in less than three minutes.