Dan Slevin reviews four new films in cinemas: Emilia Pérez is a musical about Mexican cartel boss who goes through gender reassignment; Flow is an animated film from Latvia about a cat and his animal friends escaping a catastrophic flood; Dragonkeeper is an animated Chinese-Spanish co-production with the voices of Bill Nighy and Bill Bailey, and Gerard Butler and O’Shea Jackson Jr. reunite for the sequel to Den of Thieves, Pantera.