Øystein Aarseth better known by his stage name Euronymous, was a Norwegian musician and a founder of and central figure in the early Norwegian black metal scene. He was a co-founder and guitarist of the Norwegian black metal band Mayhem and was the only constant member from the band's formation in 1984. Personality. In the view of the public eye, Euronymous was described as an angry and serious individual. Though band-mates and friends referred to him as a fun and talkative person