Well, that Panda may be cute, but he tears apart Lee like a panda eating a toast (yeah I know). The strategy is just to shield him, and when he dies, let the Panda hit 3 times Ken or Rei, so they can activate their spells (teleport or invisibility). When theyre low, give them a boost of health, and always help them with your shield (Ken's Shield) because you will survive depending on your dodges and how long can those 2 survive until they eventually gently kill the big guy. Good Luck!