Complex sentence: Harald Nævdal (born 6 July 1970) known as Demonaz Doom Occulta, or most widely known simply as Demonaz, is most recognized as the once-guitarist and chief lyricist for the Norwegian black metal band Immortal.
Split into simpler sentences: Harald Nævdal (born 6 July 1970) known by his stage names Demonaz Doom Occulta and Demonaz, is a Norwegian musician. He most recognized as the once-guitarist and chief lyricist for the Norwegian black metal band Immortal.