Which Wurmple's Which? - S6-E21
Revealing mistake: When turning to agree with Brock, May and Max duplicate. (00:07:19)
On a Wingull and a Prayer - S6-E18
Revealing mistake: At the beginning of the episode, when Pikachu speaks, his mouth duplicates. (00:00:05)
All Things Bright and Beautifly! - S6-E13
Revealing mistake: When Ash opens a door, Pikachu's tail clips through the doorway and wall. (00:11:26)
A New Land! A New Adventure!! - S6-E1
Revealing mistake: In the English dub, during the "Who's That Pokémon?" segment, part of Lanturn's tailfin is cut off. (00:11:39)
Revealing mistake: In the English dub, towards the end of the intro, May is slightly transparent and Max's left arm can be seen through her. (00:01:54)
Try to Study! Pokémon Trainer's School! - S6-E15
Revealing mistake: When Anita says that Kenny does not care about Pokémon either, she is sitting in midair. (00:09:46)
Revealing mistake: When Ash and his friends run into the Pokémon Center, a line is briefly layered over them. (00:07:06)
Revealing mistake: As Seviper slips back into the bush after Torchic trips on its tail, the end of its tail is cut off. (00:03:16)
Try to Study! Pokémon Trainer's School! - S6-E15
Revealing mistake: When Ash says, "No problem!" in response to Roxanne asking if it is all right to postpone his match at the Rustboro Gym, Pikachu's mouth duplicates. Also, Ash and Roxanne go from being 90 centimetres from each other to being 30 centimetres away. Additionally, the former's bag goes from being present to vanishing. (00:06:18)
Revealing mistake: When Ash is first seen, his hands clip through him. (00:00:02)
Revealing mistake: When Ash says, "Seems almost magical," the end of Pikachu's tail is missing. (00:03:59)
Revealing mistake: When first revealing a Lotad, the Lotad appears from nowhere. (00:02:10)
Answer: He is a good guy but just found himself in a bad situation when he worked for Lysander. He didn't want him to harm Ash and his Pokémon when he was trying to get the special bond between Ash and his Greninja to work. He does leave Lysander and go back to being a good person.