Question: The former bassist of what influential extreme metal band, also collaborated on the non-fiction book Only Death is Real?

full_context: Document 1: Martin Bengtsson: Martin Bengtsson is a Swedish metal musician. He was a key part of the influential Swedish melodic death metal scene. He was a member of the melodic death metal band Arch Enemy between 1997 and 1998, and played bass guitar on their second album, Stigmata. He was also a member of Arch Enemy guitarist Christopher Amott's side project Armageddon in 1997.
Document 2: Dawn of the Black Hearts: Dawn of the Black Hearts is a bootleg live album by the Norwegian black metal band Mayhem. It is infamous for bearing a photograph of Mayhem's singer, Dead (Per Yngve Ohlin), after his suicide in April 1991. The photograph was taken by Mayhem's guitarist, Euronymous (Øystein Aarseth), when he discovered the body.
Document 3: De Mysteriis Dom Sathanas: De Mysteriis Dom Sathanas is the first full-length studio album by the Norwegian black metal band Mayhem. Songwriting began in 1987, but due to the suicide of vocalist Per "Dead" Ohlin and the murder of guitarist Øystein "Euronymous" Aarseth, the album's release was delayed until May 1994. "De Mysteriis Dom Sathanas" is widely considered one of the most influential black metal albums of all time.
Document 4: The Girl Who Was... Death: The Girl Who Was ... Death is the debut album by Devil Doll. Its official release date was March 4th, 1989, but there was a pre-release of cassette tapes in December 1988. This was the second album by Devil Doll, but their first to be released to the public (the group's first release, The Mark of the Beast, had only one copy pressed, to be owned by the leading band member, Mr. Doctor). The album was entirely written by Mr. Doctor and is based on a television series by Patrick McGoohan called The Prisoner. The first edition of the album was pressed into 500 copies, but only 150 would survive Mr. Doctor's strange artistic vision. The 150 copies were handed out after a live performance of the album and the remaining 350 LPs were burned by Mr. Doctor after the show. In each album handed out was a unique inlay written by Mr. Doctor personally (some, rumour has, even in his own blood). The album would later be released under several different editions throughout the years (most notably by the band's official fanclub, now the only source from which to obtain any of the band's material).
Document 5: Death's Domain: Death's Domain is a book by Terry Pratchett and Stephen Briggs, and illustrated by Paul Kidby. It is the fourth in the "Discworld Mapp" series, other publications of which include "The Streets of Ankh-Morpork, The Discworld Mapp" and "A Tourist Guide to Lancre." It was first published in paperback by Corgi in 1999. It was the second in the series to be illustrated by Kidby. As with the other "mapps", the basic design and booklet were compiled by Pratchett and Briggs.
Document 6: Thomas Gabriel Fischer: Thomas Gabriel Fischer (born 19 July 1963), also known by his stage names of Tom G. Warrior and Satanic Slaughter, is a Swiss metal musician. He is considered to be one of the pioneers of the death metal style of singing, which resembles guttural growling. He led the groups Hellhammer and Celtic Frost, and today is the frontman of the band Triptykon.
Document 7: The Gospel of Filth: The Gospel of Filth: A Bible of Decadence & Darkness (formerly known as "The Gospel of Filth: A Black Metal Bible") is a book by Dani Filth and Gavin Baddeley, documenting the history of the band Cradle of Filth and straying further afield to explore their influences and "lay bare the fascinating underworld of contemporary culture".
Document 8: God Is Dead?: "God Is Dead?" is a song by heavy metal band Black Sabbath featured on the album "13". It is the first single from the album, and the first with Ozzy Osbourne since 1998's "Psycho Man" and "Selling My Soul" from "Reunion". The song was released via an MP3 download on Amazon. It was also available as a free download to those who pre-ordered the full album on iTunes. The song in its entirety was posted on the official YouTube channel in promotion of this. Both the song title and figure on the single's cover, by Heather Cassils, are a reference to Friedrich Nietzsche, a German philosopher who is famous for saying that "God is dead. God remains dead. And we have killed him. How shall we comfort ourselves, the murderers of all murderers?".
Document 9: Only Death Is Real: Only Death Is Real: An Illustrated History of Hellhammer and Early Celtic Frost 1981–1985 is a non-fiction book written by Tom Gabriel Fischer with collaboration of Martin Eric Ain, published through Bazillion Points on March 30, 2010. The book features an introduction by Nocturno Culto of Darkthrone and a foreword by author Joel McIver.
Document 10: Martin Eric Ain: Martin Eric Ain (real name Martin Stricker, born July 18, 1967 in the US) ) is best known for being the former bassist of the influential extreme metal band Celtic Frost. He used the stage name Martin Eric Ain throughout his career in Celtic Frost.
Document 11: Martín Méndez: Martín Méndez (born April 6, 1978 in Montevideo, Uruguay) is the bass guitar player of progressive death metal band Opeth and second most constant member of the band, behind lead vocalist, songwriter and guitarist Mikael Åkerfeldt.
Document 12: Strid (band): Strid is a Norwegian black metal band that was originally known as "Malfeitor" from 1991 to 1992. After releasing two demos - "Malfeitor" (in 1991) and "Pandemonium" (in 1992), they changed their name to "Battle" and there were some line up changes at the time. In the year of 1992 the band released the "End of Life" demo. The demo contains only one song which is around 11 minutes. The line up at the time of recording the demo was: Storm - on bass and vocals, Lars Fredrik Bergstrøm - on guitars and Jardar - on drums. The guitars were written by Lars Fredrik Bergstrøm (1974 - 2014). In 1993 the band changed the name to "Strid" which means "Battle" in Norwegian. That same year, Strid re-released their "End of Life" demo under their new name, through the German label "Malicious Records". After releasing the "End of life" demo, Lars Fredrik Bergstrøm left the band and was replaced by Ravn Harjar. Through the years between 1993 and 1995, the band writes and records the self-titled EP which was released through Malicious Records and contains only two songs - "Det hviskes blant sorte vinder" which means "It Is Whispered Amid the Black Winds" in Norwegian and "Nattevandring" which means "Nightwandering" in Norwegian. The music style and sound of this demo is more ambient/atmospheric black metal oriented. Mainly because of this release, the band is commonly recognised as the creators of depressive black metal along with some other bands from the second wave of black metal music. At this time the band line up contains: Ravn Harjar - on guitars, Storm - on bass and vocals and Jardar - on drums. After the releasing of the self-titled EP, there was no any official releases by the band. There are also bootleg releases that came out through the years like the CD from 2005 by Ars Mysteriorum and LP, each featuring both "End of Life" and the self - titled EP tracks. In the year of 2001 the original former member of "Malfeitor/Battle/Strid", bass player and vocalist - Storm committed suicide. In the year of 2007, the Greek label Kyrck Productions & Armour re-released all the previous material released by the band from the past which contains all "Malfeitor/Battle/Strid" material. Somewhere between 2009 and 2010 there was a reunion of the band with old members including Vicotnik (Dødheimsgard, ex-Aphrodisiac, ex-Ved Buens Ende, ex-Manes, ex-Code, ex-Naer Mataron, ex-Endwarfment). Another member that was part of the reunion was Lars Fredrik Bergstrøm - the main composer of the "End of Life" track. In 2014 Lars Fredrik Bergstrøm died. At this time the band line up contains Ravn Harjar - on guitars and vocals, Vicotnik - on bass and Sigmund (ex-Inflabitan, ex-Dødheimsgard) - on guitars. In January 2015, Ravn Harjar wrote a statement on the official Strid Facebook page that in the autumn of the year 2015 the band will start recording their first full-length album which will be titled "Endetid". That means "End of times" in Norwegian.
Document 13: Bassic: Martin "Bassic" Lindhe (born 20 January 1971, Borås, Sweden) is a Swedish musician and composer, with a style that blends electronica, ambient and dance. His music is often progressive and suggestive in nature. He is best known for his string of hits on the music website mp3.com, where he during a period of almost two years he was one of the most downloaded artists in the genres electronica, new age, mood music and progressive trance. He moved to the United States in 1999 and currently lives in Duvall, Washington with his family. Lindhe is the great-grandchild of the Swedish composer Wilhelm Stenhammar.
Document 14: Dana Strum: Dana Strum (born Dana Strumwasser on December 13, 1958 in Washington, DC) is the bassist of glam metal band Slaughter. Before that, he was in Vinnie Vincent Invasion together with future Slaughter bandmate, Mark Slaughter. He was raised in Southern California's San Fernando Valley and began his performing career in the band Badaxe, playing regularly at the infamous Starwood along with Quiet Riot, Mötley Crüe, and others.
Document 15: Martin Rev: Martin Rev (full name Martin Reverby, born December 18, 1947) is an American musician and the instrumentalist in the rock band Suicide. He also has a solo career and has released several solo albums for a number of labels, including ROIR and Puu. His style varies widely from release to release, from electronic no wave ("Martin Rev") to bubblegum pop ("See Me Ridin," "Strangeworld") to heavy synthesizer rock ("To Live").
ground_truth: Celtic Frost