From Bulbapedia, the community-driven Pokémon encyclopedia.
Remo (Japanese: ルイ Louie) is a recurring character in the Pokémon anime who first appeared in Mega Evolution Special I.
Remo was sent to an assignment to retrieve a Mega Stone from ancient ruins by an unknown person, but as Alain found it first, Remo challenged him to a battle over the Mega Stone. When Alain accepted his challenge, he introduced himself as a Dragon Trainer, to which Alain responded that his partner, Charizard, is a Dragon type too. Remo pointed out it is amateurish to call Charizard a Dragon type, but Alain simply shrugged this off, saying that Remo was the one being an amateur. After this, both Trainers Mega Evolved their Pokémon and engaged in a fierce battle, which eventually ended in Alain's victory. After winning, Alain told Remo that he should henceforth remember that Mega Charizard X is a Fire/Dragon type.
Remo is shown to be a confident person, not hesitating to battle Alain when he discovered that he possesses a Key Stone. He also appears to be a show off person, as he seems to enjoy doing a pose while introducing himself, as well as waving his umbrella around.
This listing is of Remo's known Pokémon in the anime: