Question: What was the name of the keyboardist and songwriter who formed the electronic music group whose fifth studio album was Invaders Must Die?

full_context: Document 1: Omen (The Prodigy song): "Omen" is the nineteenth single released by the British electronic band The Prodigy. It was released on 16 February 2009, and it is the first commercial single from the album "Invaders Must Die".
Document 2: Warrior's Dance: "Warrior's Dance" is the twentieth single released by the British electronic band The Prodigy on 11 May 2009, and it is the second commercial single from the album "Invaders Must Die" after "Omen" and the free "promo" single "Invaders Must Die".
Document 3: Ultramagnetic MCs: The Ultramagnetic MCs is an American hip hop group based in Bronx, New York. Founded by Kool Keith, the group also includes Ced Gee, TR Love, and Moe Love. Tim Dog became an unofficial member in 1989. In 1990, DJ Jaycee was added as Roadmanager and backup DJ. Big.D was put down with the crew by Kool Keith in 1989. In 2006 Kool Keith and Big.D formed the supergroup The Commissioner, and in 1999 Big.D and D.J Moe-Love also formed the powerhouse group Slaughterhouse-Cartel. A former member, Rooney Roon, was fired following an assault arrest. Beat-boxing legend Rahzel was also involved with the group early in its career. The group's work was associated with unorthodox sampling, polysyllabic rhymes, and bizarre lyrical imagery.
Document 4: Smack My Bitch Up: "Smack My Bitch Up" is a song by British rave group the Prodigy. It was released in November 1997 as the third and final single from the album "The Fat of the Land". The song was voted by "Mixmag" readers as the third greatest dance track of all time. Although the song wasn't as big a commercial success as their previous singles, it gained a cult following.
Document 5: Massive Attack discography: The discography of British trip hop group Massive Attack consists of five studio albums, three compilation albums, five remix albums, one soundtrack album, five extended plays, eighteen singles and twenty-seven music videos. The group were founded in 1988 by musicians Robert "3D" Del Naja, Grantley "Daddy G" Marshall, Andrew "Mushroom" Vowles and Adrian "Tricky" Thaws in Bristol, England. Prior to the formation of Massive Attack, all three were members of British sound system The Wild Bunch.
Document 6: Pendulum (drum and bass band): Pendulum is an Australian/British drum and bass and electronic rock band founded in 2002. Pendulum originally formed in the city of Perth, Western Australia by Rob Swire, Gareth McGrillen, and Paul "El Hornet" Harding. The band was later expanded to include members, Ben Mount, Peredur ap Gwynedd, and KJ Sawka. Members Swire and McGrillen also formed the electro house duo Knife Party. The group is notable for its distinctive sound, mixing hard rock with electronic music and covering a wide range of genres.
Document 7: Die (album): Die! is the sixth album by the rapper Necro. "Die!" was initially alluded to on Necro's MySpace profile as a "brand new solo album coming September 2009"; however, on August 13, the page's header was updated with an announcement of the album's title and its release date, which was put back to May 2010. "Die!" was Necro's first album since "Death Rap" in 2007 and was released by Psycho+Logical-Records. The album's release date was finalised when the album cover was released on March 25, 2010.
Document 8: The Prodigy: The Prodigy are an English electronic music group from Braintree, Essex, formed in 1990 by keyboardist and songwriter Liam Howlett. The first line-up of the band also included Maxim (MC and vocalist), Keith Flint (dancer and vocalist), Leeroy Thornhill (dancer and live keyboardist), and female dancer and vocalist Sharky. Along with The Chemical Brothers, Fatboy Slim, and other acts, The Prodigy have been credited as pioneers of the big beat genre, which achieved mainstream popularity in the 1990s. Their style ranges from rave, hardcore techno, electro-industrial, jungle and breakbeat and big beat, adding punk vocal elements in later works.
Document 9: Take Me to the Hospital: "Take Me to the Hospital" is the twenty-first single released by the British electronic band The Prodigy. released on 31 August 2009, the CD single includes the Sub Focus remix and the 12" single also includes a Rusko remix. Liam also collaborated with Josh Homme to create the "Wreckage" mix of the song. It is the third commercial single from their fifth studio album "Invaders Must Die", after "Omen" and "Warrior's Dance", as well and the free promotional single "Invaders Must Die".
Document 10: Massive Attack: Massive Attack are an English trip hop group formed in 1988 in Bristol, consisting of Robert "3D" Del Naja, Grant "Daddy G" Marshall and formerly Andy "Mushroom" Vowles ("Mush"). Their debut album "Blue Lines" was released in 1991, with the single "Unfinished Sympathy" reaching the charts and later being voted the 63rd greatest song of all time in a poll by "NME". 1998's "Mezzanine", containing "Teardrop", and 2003's "100th Window" charted in the UK at number one. Both "Blue Lines" and "Mezzanine" feature in "Rolling Stone"' s list of the 500 Greatest Albums of All Time.
Document 11: Music of the United Kingdom (1990s): Popular music of the United Kingdom in the 1990s continued to develop and diversify. While the singles charts were dominated by boy bands and girl groups, British soul and Indian-based music also enjoyed their greatest level of mainstream success to date, and the rise of World music helped revitalise the popularity of folk music. Electronic rock bands like The Prodigy and Chemical Brothers began to achieve a high profile. Alternative rock reached the mainstream, emerging from the Madchester scene to produce dream pop, shoegazing, post rock and indie pop, which led to the commercial success of Britpop bands like Blur and Oasis; followed by a stream of post-Britpop bands like Travis and Feeder.
Document 12: Invaders Must Die (song): "Invaders Must Die" is the eighteenth single released by the British electronic band The Prodigy. It was released from the band's website as a free digital download on 26 November 2008. It was the first single from the album "Invaders Must Die". The download was announced on 24 November, in a newsletter sent to fans, and first aired on Zane Lowe's Radio 1 show as his 'Hottest Record in the World' on 26 November. The song was co-produced by Does It Offend You, Yeah?'s James Rushent. Liam Howlett described this to the Dubai edition of Time Out as: "a very abrasive-sounding electronic track, kind of different to anything we've done before." Although not being a commercial single the track charted at 49 in the UK Singles Chart on 1 March 2009, whilst the Chase & Status Remix reached 53 in the Australian Aria Singles Chart and 7 in the Aria Dance Chart. On 30 November 2009 the re-amped version by Liam was released as an EP with the B-side Mescaline, and Thunder remixes.
Document 13: Skinny Puppy: Skinny Puppy is a Canadian industrial music group formed in Vancouver, British Columbia in 1982. The group is widely considered to be one of the founders of the electro-industrial genre. Initially envisioned as an experimental side project by cEvin Key (Kevin Crompton) while he was in the new wave band Images in Vogue, Skinny Puppy evolved into a full-time project with the addition of vocalist Nivek Ogre (Kevin Ogilvie). Over the course of a dozen studio albums and many live tours, Key and Ogre have been the only constant members. Other members have included Dwayne Goettel (1986–1995), Dave "Rave" Ogilvie (long-time associate, producer, and "unofficial" fourth member until 1995), Mark Walk (2003–present), and a number of guests, including Bill Leeb (1985–1986, under the pseudonym Wilhelm Schroeder), Al Jourgensen (1989), and many others.
Document 14: Document 5: Document #5 is the first full length album by hardcore punk band Pg. 99, released in 2000 through Reptilian Records. The album was released on vinyl and CD formats, the vinyl version was released in limited quantities, with 666 copies made. 200 copies were on grey marble vinyl, while the rest were standard black vinyl. Reptillian Records announced that the album would be reissued on LP format in the summer of 2015, however it's release date was pushed back to October 27, 2017 to coincide with the band's reunion tour. The reissue was released on compact disc, vinyl, and digital formats.
Document 15: Invaders Must Die: Invaders Must Die is the fifth studio album by English electronic dance music group The Prodigy. The album was released on 23 February 2009 on the band's new record label Take Me to the Hospital, and was distributed by Cooking Vinyl.
ground_truth: Liam Howlett