Question: Who worked on most different areas, Ali Campbell or Mr Lordi?

Context paragraphs:
Areas of mathematics: Mathematics encompasses a growing variety and depth of subjects over history, and comprehension requires a system to categorize and organize the many subjects into more general areas of mathematics.  A number of different classification schemes have arisen, and though they share some similarities, there are differences due in part to the different purposes they serve.  In addition, as mathematics continues to be developed, these classification schemes must change as well to account for newly created areas or newly discovered links between different areas.  Classification is made more difficult by some subjects, often the most active, which straddle the boundary between different areas.

List of professional institutions in management: Professional institutions are the societies and associations, they help develop and promote a career and the people who practice in it.  There are many chartered professional institutes in the UK, over 80, that cover many different areas of work.  The different areas of work that are covered includes constructions, health, journalism, personnel, finance, engineering, law and of course, management.  The professional institutes can help you both before and after you graduate.

Duncan Campbell (UB40): Duncan Campbell (born 3 April 1958 in Birmingham) is an English musician and current lead singer of the reggae band, UB40.  He joined the band in 2008 after the departure of his brother Ali Campbell.

Gibraltar Music Festival: The Gibraltar Music Festival, as of 2017 known as MTV Presents Gibraltar Calling, is an annual music festival held in the British Overseas Territory of Gibraltar.  The Government of Gibraltar's Ministry of Culture confirmed on 10 August 2012, that the inaugural event would be held on 8 September 2012 at Victoria Stadium.  The first festival had a British artist, Jessie J, as headlining act.  The rest of the lineup consisted of Ali Campbell from UB40, and local bands Noiz and Jetstream.

My Way (Lady Saw album): My Way is the seventh studio album by Jamaican recording artist Lady Saw.  The album featured guest artists such as Eve, Camar Doyles, & Ding Dong.  A duet with Ali Campbell on "I Do Love You" was recorded for the album, but not included on the final track listing.

Sants-Montjuïc: Sants-Montjuïc (] ) is one of the ten districts Barcelona has been split in since 1984, numbered District 3.  Comprising very different areas of the city, it covers the southern part of Barcelona, joining the two former districts "II" (made up by Montjuïc and Poble-Sec) and "VII" (Sants - Hostafrancs - La Bordeta), as well as the different areas comprised in the Zona Franca.  As of the 2005 census it had a population of 177,636.  It borders Les Corts, Eixample, Ciutat Vella, and the municipalities L'Hospitalet de Llobregat and El Prat de Llobregat.

Lordi: Lordi (] ) are a Finnish hard rock/heavy metal band, formed in 1992 by the band's lead singer, songwriter and costume maker, Mr Lordi.  In addition to their melodic metal music, Lordi are also known for wearing monster masks and using horror elements with pyrotechnics during concerts and music videos.

Labour of Love IV: Labour of Love IV is the seventeenth album and fourth covers album by UB40, released on the Virgin Records label in 2010.  It is the first UB40 album not to feature the classic line-up as longtime UB40 vocalist/guitarist Ali Campbell and keyboardist Mickey Virtue both departed the band in 2008; consequently it is the first album by the band to feature vocalist Duncan Campbell.

Ali Campbell: Alistair Ian "Ali" Campbell (born 15 February 1959) is an English singer and songwriter who was the lead singer and a founding member of the English reggae band UB40.  As part of UB40, Campbell sold over 70 million records worldwide and toured the globe for 30 years.  In 2008, Campbell left UB40 and embarked on a solo career.  In 2012, Campbell was announced as one of the three judges on the judging panel of the TV show, "New Zealand's Got Talent".  In August 2014, Campbell announced that he had reunited with former UB40 band mates Astro and Mikey to record a new album, "Silhouette", released on 6 October 2014.

Mr Lordi: Tomi Petteri Putaansuu (born 15 February 1974) is a Finnish musician, businessman, special effect make-up artist, songwriter, actor, painter, comics artist and graphic designer.  He is best known by his stage name Mr Lordi a.k.a. Mr L.

Supporting paragraphs: Ali Campbell Mr Lordi
Answer: Mr Lordi