Question: Who developed the television series of which the fifteenth episode of the second season was "Wrath of the Villains: Mad Grey Dawn"?

full_context: Document 1: Rise of the Villains: Knock, Knock: "Rise of the Villains: Knock, Knock" is the second episode of the second season and 24th episode overall from the FOX series "Gotham". The episode was written by Ken Woodruff and directed by Rob Bailey. It was first broadcast in September 28, 2015 in FOX. In this episode, Gordon is assigned in investigating the Arkham escapees, now calling themselves "the Maniax". Meanwhile, Bruce is getting closer to the truth about his father's office.
Document 2: Selina Kyle (Gotham): "Selina Kyle" is the second episode of the television series "Gotham". It premiered on FOX on September 29, 2014 and was written by series developer Bruno Heller and directed by Danny Cannon. In the episode, Gordon (Benjamin McKenzie) and Bullock (Donal Logue) investigate a child trafficking ring in Gotham City while Cobblepot (Robin Lord Taylor) begins to make his way back to Gotham, leaving victims in his path.
Document 3: List of Gotham characters: "Gotham" is an American crime television series developed by Bruno Heller, based on characters appearing in and published by DC Comics in their Batman franchise, primarily those of James Gordon and Bruce Wayne. The series premiered in the United States on September 22, 2014 on Fox television network. The series stars Ben McKenzie as the young Gordon, while Heller executive produces along with Danny Cannon, who also directed the pilot.
Document 4: Wrath of the Villains: Prisoners: "Wrath of the Villains: Prisoners" is the sixteenth episode of the second season, and 38th episode overall from the Fox series "Gotham". The episode was written by executive producer Danny Cannon and directed by Scott White. It was first broadcast on March 28, 2016. In the episode, Gordon is sent to prison after being framed by Nygma into the murder of Theo Galavan and Carl Pinkney. Meanwhile, Cobblepot continues to bond with his father while his stepmother and step-siblings plan to kill him. This episode also has the fewest cast members as only Ben McKenzie, Donal Logue, Robin Lord Taylor and Cory Michael Smith appear.
Document 5: List of Gotham episodes: "Gotham" is an American crime-drama television series developed by Bruno Heller, based on characters appearing in and published by DC Comics in their Batman franchise, primarily those of James Gordon and Bruce Wayne. The series stars Ben McKenzie as the young Gordon, while Heller executive produces along with Danny Cannon, who also directed the pilot. As originally conceived, the series would have served as a straightforward story of Gordon's early days on the Gotham City Police Department.
Document 6: Gotham (TV series): Gotham is an American crime drama television series developed by Bruno Heller, based on characters published by DC Comics and appearing in the Batman franchise, primarily those of James Gordon and Bruce Wayne. The series stars Ben McKenzie as the young Gordon, while Heller executive-produces, along with Danny Cannon, who also directed the pilot.
Document 7: Wrath of the Villains: Mad Grey Dawn: "Wrath of the Villains: Mad Grey Dawn" is the fifteenth episode of the second season, and 37th episode overall from the Fox series "Gotham". The episode was written by Robert Hull and directed by Nick Copus. It was first broadcast on March 21, 2016. In the episode, Gordon and Bullock investigate a pair of clues in a museum, unaware Edward Nygma is the perpetrator. Meanwhile, Bruce continues living in the streets with Selina and Cobblepot meets a man who knew about his mother.
Document 8: Wrath of the Villains: Mr. Freeze: "Wrath of the Villains: Mr. Freeze" is the twelfth episode of the second season, 34th episode overall and the mid-season premiere from the FOX series "Gotham". This episode is also the first episode to use the subtitle "Wrath of the Villains". The episode was written by Ken Woodruff and directed by Nick Copus. It was first broadcast in February 29, 2016 in FOX. In the episode, having just killed Galavan, Gordon returns to the GCPD, who's currently investigating a killing spree of a man who freezes people. Meanwhile, Cobblepot pays the consequences of killing Galavan.
Document 9: Gotham Central: Gotham Central is a police procedural comic-book series that was published by DC Comics. It was written by Ed Brubaker and Greg Rucka, with pencils initially by Michael Lark. The story focused on the Gotham City Police Department and the difficulties of its officers living and working in Gotham City, home of Batman.
Document 10: Bruce Wayne (Gotham): Bruce Wayne is a fictional character appearing in the Fox series "Gotham". The Bruce Wayne character is the alter-ego of the superhero Batman, created by Bill Finger and Bob Kane, as "Gotham" portrays Bruce's teenage years and transition into adapting the Batman persona in later years. "Gotham" marks the second time Batman was adapted for television after the 1960s Batman series, though the lead character is James Gordon. Bruce is portrayed by David Mazouz.
Document 11: James Gordon (Gotham): Detective 1st Grade James "Jim" Gordon is a fictional character that appears in the Fox TV series "Gotham". He is portrayed by Ben McKenzie. He is based on the character of the same name created by Bill Finger, but credited to Bob Kane, that debuted in the first panel of "Detective Comics" #27 (May 1939).
Document 12: Gotham (season 4): The fourth season of the American television series "Gotham", based on characters from DC Comics related to the Batman franchise, revolves around the characters of James Gordon and Bruce Wayne. The season is produced by Primrose Hill Productions, DC Entertainment, and Warner Bros. Television, with Bruno Heller, Danny Cannon, and John Stephens serving as executive producers. The first half of the season will be inspired by the comic book story "", and the second half by "". The subtitle for the first half of the season is "A Dark Knight".
Document 13: Wrath of the Villains: Transference: "Wrath of the Villains: Transference" is the twenty-second episode and season finale of the second season, and 44th episode overall from the Fox series "Gotham". This is also the last episode in the series with the subtitle "Wrath of the Villains". The episode was written by developer and showrunner Bruno Heller and directed by Eagle Egilsson. It was first broadcast on May 23, 2016. In the episode, Lucius and Bruce are being held in a room by Nygma, ready to kill them unless they tell him information. Meanwhile, Gordon tries to stop Professor Strange once and for all while Basil Karlo begins to fake being Gordon after his experiment. The episode marked the end of the Strange story arc, which culminated with his arrest. The episode is also dedicated to the memory of Doug Kraner, production designer of the show, who died on April 4, 2016 at the age of 65 of cancer.
Document 14: Rise of the Villains: Worse Than a Crime: "Rise of the Villains: Worse Than a Crime" is the eleventh episode of the second season, 33rd episode overall and the mid-season finale from the FOX series "Gotham". This episode is also the last episode to use the subtitle "Rise of the Villains". The episode was written by series developer Bruno Heller and directed by Jeffrey Hunt. It was first broadcast in November 30, 2015 in FOX. In the episode, Gordon has his final showdown against Galavan, who has kidnapped Bruce to end the legacy of his family.
Document 15: Wrath of the Villains: Pinewood: "Wrath of the Villains: Pinewood" is the eighteenth episode of the second season, and 40th episode overall from the Fox series "Gotham". The episode was written by co-executive producer Robert Hull and Megan Mostyn-Brown and directed by executive producer John Stephens in his first "Gotham" episode directed. It was first broadcast on April 18, 2016. In the episode, Bruce and Alfred set to find out information about a program called Pinewood Farms which had something to do with Thomas Wayne's death and involvement while Gordon sets out to find The Lady and Dr. Strange continues his experiments.
ground_truth: Bruno Heller