Question: Karl Sanders was a vocalist for a metal band whose lyrics were inspired by what type of mysticism?

Context articles: Karl Sanders
Saurian Meditation
Militia Christi (band)
Saurian Exorcisms
Black Seeds of Vengeance
Deas Vail
Portal (band)
Nile (band)
Otrazhenie
Nile discography

Karl Sanders (born June 5, 1963) is an American musician, most widely known as the founding member of the American ancient Egyptian-themed technical death metal band Nile.
 He was born in California, and lives in Greenville, South Carolina.
 Sanders is endorsed by Dean Guitars, and currently has a signature guitar with the company.
Saurian Meditation is the first solo album by Karl Sanders, the vocalist/guitarist of the  technical death metal band Nile.
 It was released on 26 October 2004 through Relapse Records.
 The music is a full length exploration of the atmospheric interludes heard on Nile's previous albums, and still draws on ancient Babylonia and Lovecraftian themes for inspiration.
 The album was well received by metal and non-metal listeners alike.
Militia Christi is an Italian gothic rock/dark ambient musical project whose lyrics, sung in Italian and Latin, deal with Mysticism, Gnosticism, Hermetism, Rosicrucianism, Alchemy, Theosophy, Philosophy, Knights Templar and Freemasonry.
 They seem to have a very strong connection with the Italian extreme gothic metal band Theatres des Vampires.
Saurian Exorcisms is the second solo album by Karl Sanders, the vocalist/guitarist of the death metal band Nile.
 It was released on 14 April 2009 through The End Records.
 The music is a full length exploration of the atmospheric interludes heard on Nile's previous albums, and still draws on ancient Iraki themes for inspiration.
 He has also now drawn inspiration from other types of music such as Tibetan, Indian and Arabic.
Black Seeds of Vengeance is the second album by American  technical death metal band Nile.
 The album was released on September 5, 2000 through Relapse Records.
 "Black Seeds of Vengeance" marks the first album in Nile's discography to feature extensive liner notes in the booklet, written by Karl Sanders to explain the concept and themes behind each song.
 The band also began undertaking an even more complex musical direction from the last album.
 This is also the first Nile album to feature the vocal and guitar talents of Dallas Toler-Wade, who has performed on all subsequent Nile albums, as well as the first and only appearance of Derek Roddy on a Nile album as a session drummer only.
 He performs on all tracks except for "To Dream of Ur".
 Prior to recordings, Pete Hammoura left the band due to injuries sustained while touring.
Deas Vail ( ) is an alternative rock band whose lyrics are influenced by their members' Christian faith.
 The band's name is a combination of Latin and old French, roughly translated as "humble servant of God."
 Their eponymous third full-length album earned them slots at Bonnaroo and a headlining performance at CMJ.
Portal is an Australian extreme metal band whose style is an unorthodox fusion of death metal with black metal.
 The band's hybrid musical style is characterised by heavily distorted guitar riffs, down-tuned rhythms, and vocals ranging from "menacing, echoing" sound effects to guttural grunts.
 Writing for "Popmatters", Adrien Begrand noted that "death metal always pretends to be scary, but [...] it's all rather harmless.
 That said, however, I make no mistake in saying that the death metal peddled by Australia’s Portal is truly friggin' terrifying".
 Lead guitarist Horror Illogium has described Portal's intent as "to capture a cinematic horror scope".
 They have released four full-length albums to date, as well as a number of EPs and split releases.
 Their most recent album, "Vexovoid", was released in February 2013 on Profound Lore Records.
Nile is an American death metal band from Greenville, South Carolina, United States, formed in 1993.
 Their music and lyrics are inspired by Ancient Egyptian/Near Eastern mysticism, history, religion, and ancient art, as well as the works of H.P. Lovecraft.
Otrazhenie (Russian: Отражение ) was a Belarusian heavy metal band from the city of Mozyr, the first professional independent (not state sponsored) Belarusian rock band whose music and lyrics inspired and instigated the birth and development of Belorussian rock music.
The discography of the band "Nile" consists of eight studio albums, two compilations, three extended plays (EP), two demos, three singles, and five music videos. Nile is an American technical death metal band from Greenville, South Carolina formed in 1993.
 Since 2007, their formation consists of Karl Sanders (guitars, vocals), Dallas Toler-Wade (vocals, guitars), George Kollias (drums, percussion), and Chris Lollis (bass, vocals) (live member 2007–2010).
 Two years later, they followed up with "Festivals of Atonement", an EP released through their own Anubis Records label.
 In 1996, "Ramses Bringer of War" was released, a three-track demo with the title inspired by Gustav Holst's classical work "Mars, Bringer of War".
 The following year, the "Ramses" demo was re-released by Visceral Productions on EP format.