Details: One of the ten possible challengers you will face as you sit on the Champion's Chair in the Champion's Hall after defeating the Elite Four is your rival Hau. He has finally defeated the Island Challenge, as well as the Elite Four, and he wants a Rematch for all the matches he has had with you prior to this. His team still varies depending on your Starter, growing in both size and levels, not focusing on any given type.
Challenger Hau (Rowlet Starter) - Level 63 Raichu, Level 63 Flareon, Level 63 Komala, Level 63 Crabominable, Level 63 Primarina w/Waterium Z
Challenger Hau (Litten Starter) - Level 63 Raichu, Level 63 Vaporeon, Level 63 Komala, Level 63 Crabominable, Level 63 Decidueye w/Grassium Z
Challenger Hau (Popplio Starter) - Level 63 Raichu, Level 63 Leafeon, Level 63 Komala, Level 63 Crabominable, Level 63 Incineroar w/Firium Z