Michel

Michel was a Hollow created by the Unnamed Female Arrancar as part of her scheme to destroy Karakura Town.
Before revealing his true motives, Michel pretended to be very friendly and kind. He always smiled and was happy to help anyone. He broke away from a group of people wanting his autograph to ask Kon if he was okay after their encounter with a Hollow. He expressed care for the people of Karakura Town and mentioned how great it was that they had the Karakura-Raizer Team.
In truth, however, he was just manipulative. Using his hypnosis, he sought to bring down Karakura Town. He told the Karakura-Raizer Team that he was giving them special flying capes, but in reality, they absorbed reiatsu, weakening them so he could more easily deal with them.