After winning your fourth Gym Badge, you will find Hop on your way to the Stow-on-Side monument. At this point in the game, Hop is feeling pretty down about losing to you (and others) so many times, feeling as though he is bringing down the reputation of his brother. He'll challenge you to yet another battle, insisting that he is going to try many different things against you this time in battle. And his Pokemon Team will look incredibly different (but just for this battle), with him using three Pokemon he has never used before. Once defeated, Hop will says he will continue to try harder.