Bellatrix Lestrange
Background
Bellatrix Lestrange nee Black is a prisoner in Azkaban. She is a Death Eater and tortured and killed the parents of Neville Longbottom. Her sister is Narcissa Malfoy, her brother-in-law is Lucius Malfoy, her nephew is Draco Malfoy and her cousin is Sirius Black.
During the events of Harry Potter and the Order of the Phoenix (2007) played by Helena Bonham Carter
Thunder rages outside Azkaban and the Death Eater tattoo on Azkaban Death Eater's and Bellatrix's arm starts to come alive. Azakaban prison explodes allowing the prisoners to flee. Harry Potter, Hermione Granger, Ron Weasley, Ginny Weasley, Neville, and Luna Lovegood take the elevator to the Department of Mysteries and Neville finds a globe of prophecy with Harry's name on it. Harry picks up the prophecy which states that neither him or Voldemort can survive while the other lives. They are surrounded by Death Eaters, including Lucius Malfoy, who reveals to Harry that Voldemort tricked him and Sirius was not in danger. They demand the prophecy and a running battle starts. Harry and the others escape to the room of the Veil where they are surrounded by the Death Eaters and his friends are captured. The Order of the Phoenix arrive and another battle starts. The prophecy is destroyed when Lucius drops it. Bellatrix casts the Avada Kedavra spell against Sirius, hurtling him towards the Veil, which absorbs him. Harry chases after Bellatrix and is about to kill her when Voldemort shows up and tries to convince Harry to kill her. Dumnbledore arrives and attacks Voldemort.