Question: What kind of audience numbers does the work that inspired The Black Halo have?

Context articles: Halo 4: Forward Unto Dawn
Arbiter (Halo)
The Black Halo
Goethe's Faust
Elmo Nüganen
Epica (Kamelot album)
Silverthorn (album)
Mari (singer)
Assembly (events promoter)
History of Hollyoaks

Halo 4: Forward Unto Dawn is a military science fiction web series set in the universe of the "Halo" franchise.
 "Forward Unto Dawn" consists of five 15-minute episodes released weekly starting on October 5, 2012, and was later released as a single film on DVD and Blu-ray and was later put on Netflix in 2013.
 The series was produced as a marketing effort for the video game "Halo 4" intended to widen the audience of the "Halo" series and as a stepping stone to a potential "Halo" film.
 It was written by Aaron Helbing and Todd Helbing, and directed by Stewart Hendler.
 "Forward Unto Dawn" was shot in Vancouver over 25 days in May 2012 on a budget just under US$ .
 It has just under 500 shots with computer generated imagery, approximately a quarter of what a feature film would have, but the visual effects received praise from reviewers.
In the "Halo" science fiction universe, the Arbiter is a ceremonial, religious, and political rank bestowed upon alien Covenant Elites.
 In the 2004 video game "Halo 2", the rank is given to a disgraced commander as a way to atone for his failures.
 Although the Arbiter is intended to die serving the Covenant leadership, the High Prophets, he survives his missions and the Prophets' subsequent betrayal of his kind.
 When he learns that the Prophets' plans would doom all sentient life in the galaxy to extinction, the Arbiter allies with the Covenant's enemies—humanity—and stops the ringworld Halo from being activated.
 The Arbiter is a playable character in "Halo 2" and its 2007 sequel "Halo 3"; a different Arbiter appears in the 2009 real-time strategy game "Halo Wars", which takes place 20 years before the events of the main trilogy.
The Black Halo is the highly acclaimed, seventh full-length album by the American power metal band Kamelot.
 It was released on March 15, 2005, through Steamhammer Records.
 It is a concept album inspired by Goethe's Faust.
 Continuing the story introduced in "Epica" (2003), it is the second and final record in Kamelot's two-part rock opera about Ariel (a character based on Heinrich Faust).
 Epica tells Part 1 while The Black Halo tells Part 2.
 Goethe's Faust is also broken into two parts.
 The Black Halo features guest appearances by Simone Simons (Epica), Shagrath (Dimmu Borgir), Jens Johansson (Stratovarius), and several others.
 The album was released on vinyl in the spring of 2009, along with "Ghost Opera" (2007).
Johann Wolfgang von Goethe's Faust is a tragic play in two parts usually known in English as "Faust, Part One" and "Faust, Part Two".
 Although rarely staged in its entirety, it is the play with the largest audience numbers on German-language stages.
 "Faust" is considered by many to be Goethe's "magnum opus" and the greatest work of German literature.
Elmo Nüganen, born 15 February 1962 in Jõhvi, is an Estonian theatre director, film director and actor.
 He has been the artistic director of the Tallinn City Theatre since 1992.
 He was a professor at the Estonian Academy of Music and Theatre in 1998-2002 and 2008-2012.
 He directed the war films "Names in Marble" from 2002 and "1944" from 2015.
 "1944" had the highest opening-week audience numbers in Estonian film history and became the country's submission for the Academy Awards.
Epica is the sixth full-length album by the American power metal band Kamelot, released on March 3, 2003 through Noise Records.
 It was the first concept album by Kamelot.
 This album, along with its sequel "The Black Halo" (2005), is a rock opera inspired by the story of Goethe's Faust.
 Epica tells Part 1 while The Black Halo tells Part 2.
 (Goethe's Faust has two parts.)
 Most of the lyrics were written before the actual music was composed.
 The album inspired the naming of the band Epica after its release.
Silverthorn is the tenth studio album by the American power metal band Kamelot.
 The album was released on the Steamhammer label, a division of SPV, on October 2012 worldwide.
 It is the first album to feature Tommy Karevik as the lead singer and their third concept album, after "Epica" (2003) and "The Black Halo" (2005).
 The concept and story are original, and features a 19th-century little girl named Jolee, who dies in a tragic accident witnessed by her twin brothers.
 The story deals with how the girl's affluent family handles the tragic event, leading to cover-ups, secrets, and betrayal.
 The cover by Stefan Heilemann shows Jolee, the main character and angel of afterlife, as an adult.
Mari Youngblood (born Mary Schreck), also called Mari, is an American soprano vocalist.
 She is mostly known for her role as Helena on Kamelot's "Epica" and "The Black Halo" albums, along with her live performance on "One Cold Winter's Night" album and DVD.
 Mari has also performed as lead in numerous musicals, including Kismet, Teko, Bismil, Oklahoma, Brigadoon and many more.
 Mari is married to Kamelot's guitarist Thomas Youngblood.
Assembly is a theatre and comedy promotion company, producer and venue operator.
 It programmes and promotes entertainment events at venues in Edinburgh, London and Brighton, and is the longest-established of the so-called Big Four promoters at the Edinburgh Festival Fringe in August.
 Year-round audience numbers at Assembly events are more than 500,000, and the company's artistic director is William Burdett-Coutts.
"Hollyoaks" began airing on Channel 4 in the United Kingdom on 23 October 1995.
 The target audience was that of teenagers and it initially dramatised the lives of seven of that age group who lived in Hollyoaks, a fictional suburb in the city of Chester in Cheshire, England.
 Originally broadcast as one episode per week, in 2011 it is being shown five times weekly.
 Audience numbers have varied over its lifespan, with viewing figures well below one million being contrasted with highs of four million.