Sven Erik Kristiansen

Sven Erik Kristiansen (born 4 February 1969) is a Norwegian musician. He is best known as the former vocalist in the black metal band Mayhem under the stage name Maniac.

Kristiansen has three children, two daughters whom the youngest one is with his wife, Japanese musician Eri Isaka aka Vivian Slaughter from Gallhammer, and a son with his ex-girlfriend, Hilma. He has said that since he became a father, he has become more conscious of what he exposes himself to and less destructive.

For several years, Kristiansen was a self-admitted alcoholic. His turning point, he says, was one day when he found himself hanging by one arm out of a fourth floor window, with no idea how he got there. He is married to Vivian Slaughter, bassist and vocalist for the Japanese band Gallhammer.

He joined Mayhem in 1986 after the departure of the band's original vocalist Messiah. He was in the band until 1988, when he was replaced by Kittil. When Hellhammer decided to revive Mayhem in 1995 after the deaths of both Euronymous and Dead and the imprisonment of Count Grishnakh, he invited Maniac to return as the band's vocalist.

He was known for giving extremely intense live performances. He would often cut himself onstage, frequently landing him in intensive care units. However, "...when we realized that the cutting had become a phenomenon people came to watch, I quit doing it." He has also stated that the coverage Mayhem has received is disproportionate.

Maniac was in the band until 2004 when he was forced to leave. His erratic behavior was the main reason for this. In the only press release about the split, he also cited lack of time as being a vital factor.

Just months before he joined Mayhem he released the first issue off his fanzine Damage Inc. in 1986. Second issue came in 1987 after he had joined Mayhem. Both issues include interviews with Mayhem among other things. He is currently a member of extreme metal band Skitliv, participated as a session member for Shining, did vocals for hardcore punk band Bomberos and shares an ongoing experimental music project called Sehnsucht alongside Vivian Slaughter.