Michael, you might not survive this round, but good job anyway. Let's see what you can do in the meantime! Use Yawn on Oliver, then use Ice Beam on Mia, then use Surf to hit both Pokémon! If either Oliver or Mia uses a super-effective attack on you, use Protect, pushing the remaining actions back. Only make this substitution once!
Cappy, start out with Dig on Mia, then Return on Mia, and then Dig on Mia. If Michael is alive and uses Surf as his third action, use an evasive Dig to avoid damage if at all possible!
If Mia faints, both of you direct all attacks at Oliver instead! Good luck!