After taking the Wedgehurst Train to the Isle of Armor, you will meet up with Klara (Sword) or Avery (Shield) once again. They have been designated to take you as their apprentice for the Master Dojo found on the island. However, before heading there, they will want to see if you are strong enough to train at the Master Dojo, so they will challenge you to a battle. Like all Trainer Battles and Wild Pokemon Encounters on the Isle of Armor, the Pokemon Levels will vary depending on if you have already defeated the Main Story of the entire game. After defeating Klara/Avery, they will discourage you from going to the Master Dojo in fear of your strength.
Pokemon Trainer Klara (Sword): Level 10/58 Venipede, Level 12/60 Galarian Slowpoke
Pokemon Trainer Avery (Shield): Level 10/58 Abra, Level 12/60 Galarian Slowpoke