Question: The Black Halo features a guest appearance by a Dutch symphonic metal band, that was founded by who?
Context: Invisible Circles is the third studio album by Dutch symphonic metal band After Forever.  It was released on 25 March 2004, by the small Dutch label Transmission Records.  It is After Forever's first full-length album since the dismissal of guitarist and composer Mark Jansen, whose musical tastes had strongly influenced the sound of their first work "Prison of Desire" (2000) and their successful second offering "Decipher" (2001).  In this work After Forever choose a new musical direction, mostly revolving around elements of progressive metal instead of the gothic and symphonic metal of previous albums.  The creative process for "Invisible Circles" took more than a year and required the use of three recording studios in the Netherlands and Germany.  A long tour to support the album brought the band to some of the most important European rock festivals and to Central and South America. Epica is a Dutch symphonic metal band, founded by guitarist and vocalist Mark Jansen after his departure from After Forever. The Classical Conspiracy is the second live album released by the Dutch symphonic metal band Epica.  The recorded live show took part in Miskolc, Hungary on 14 June 2008 in the framework of the Miskolc Opera Festival, where the Swedish symphonic metal band Therion had done a similar show a year before.  Epica performed on stage with a 40-piece orchestra and a 30-piece choir, entirely composed of Hungarian musicians conducted by Zsolt Regos.  The expanded ensemble played classical music, excerpts from operas and movie soundtracks, as well as Epica's songs.  The album was released on 8 May 2009 through Nuclear Blast Records. David Martijn Westerholt (born 30 March 1979 in Waddinxveen, Netherlands) is the cofounder (along with Charlotte Wessels), keyboardist, and the main songwriter of the Dutch symphonic metal band Delain.  He was previously a member of symphonic metal band Within Temptation, until he was diagnosed with infectious mononucleosis shortly after the release of Within Temptation's second full-length studio album, "Mother Earth".  His brother Robert Westerholt is the guitarist and founder of Within Temptation.  He currently lives in Zwolle, where he resides since his study in Communication at Windesheim College in 1998. 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). 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. Within Temptation is a Dutch symphonic metal band founded in April 1995 by vocalist Sharon den Adel and guitarist Robert Westerholt.  They have always been classified by critics as gothic metal, although the "gothic" influence varies with each album.  Their most prominent and well-known sound is described as symphonic metal, although their earlier material, such as debut album "Enter", was mostly gothic metal.  "Enter" even had a hint of doom metal.  In an interview, Den Adel said they fell into a symphonic rock genre with various influences.  In a later interview with Dutch music platform 3VOOR12, den Adel stated that "we consider ourselves more a symphonic rock band ... in my opinion, we are no gothic band". Dunwich is an Italian symphonic/gothic metal band founded in Rome in 1985.  Dunwich were among the first to use a female vocalist and symphonic music elements, especially brass instrument.  Rockeramagazine considers them forerunners of the modern symphonic metal, defining them as the "first symphonic metal band". Consign to Oblivion is the second studio album by Dutch symphonic metal band Epica, and was released in 2005.  The song "Trois Vierges" features a guest appearance by then Kamelot vocalist Roy Khan.  The album's lyrics are inspired by the Maya civilization.  The CD was released with copy control on it.  This CD started a new collection of songs, called "A New Age Dawns".  This saga is continued on the album "Design Your Universe". King of Kings is the sixth studio album by the German symphonic metal band Leaves' Eyes.  It contains guest appearances of a.o. Simone Simons from the Dutch symphonic metal band Epica and Lindy-Fay Hella from the Norwegian dark folk act Wardruna.  It is their last album with Liv Kristine on vocals.
Answer: Mark Jansen