|Born in 1977 in Norway, Olaissen started his music career with Satyricon as their live guitarist from 1996 to 1999. He had only played guitar for three years when he joined them and this was his first band (as well as his first live experiences). At the time he was only 18 years old.
Olaissen wanted to form his own band and in 1997 founded Scariot. The band released 4 albums, with "Momentum Shift" featuring bassist Steve DiGiorgio. The band followed the heavy/thrash/prog metal format somewhat inspired by Nevermore. In 2005 Olaissen folded the band but released "Momentum Shift" in 2007 with session musicians, leading many to believe the band is still active with only Olaissen as an official member.
Olaissen states that he has always had a passion for extreme music and while playing in Satyricon he started working on death metal outfit Blood Red Throne in 1998. The band is still going with "Souls Of Damnation" released in 2009, the band's fifth full-length album; in addition to the various European tours, this is what Olaissen believes to be his most significant musical project to date.
His other main band, Zerozonic, was put together in 2004. Olaissen is working on the band's follow-up to 2007 release "Dead On Arrival". Other bands and projects that Olaissen is involved with include Cobolt 60, which is a joint effort on behalf of Olaissen, Flemming Gluch and Morten of Blood Red Throne fame. Cobolt 60 released "Meat Hook Ballet" in 2002 before changing their name to Trioxin (which resulted in the addition of Blood Red Throne vocalist Osvald "Vald" Egeland and bassist Erlend Caspersen) as the Blood Red Throne line-up changed. Olaissen is also involved with an '80s metal band called Big City, claiming it's "just for fun" and cites it as another way to release his creative ideas.
Olaissen has used Jackson guitars throughout most of his career, and he was signed to an endorsement deal by the company on January 26, 2010.