Vaxjo based Thrash styled Deathsters HYPNOSIA first emerged brandishing the four track April 1996 'Crushed Existence' demo tape. At this juncture the band comprised Cab Castervall on vocals and guitar, Carl-Petter Berg on second guitar, bass player Klas Gunnarsson and drummer Mike Sjöstrand. For the follow up demo, 1997's 'The Storms', HYPNOSIA lost the services of Gunnarsson and Mattias 'Slask' Werdenskog took over on bass. HYPNOSIA also had the track 'The Last Remains' included on the VOD Records compilation 'Voices Of Death'.

The February 1998 mini album 'Violent Intensity' saw a vinyl release in November of 1999 by the Dutch Soulseller Productions imprint which included an exclusive extra track in HYPNOSIA's rendition of SODOM's 'Outbreak Of Evil'. For these recordings the band numbered Cab Castervall on vocals and guitar, Johan Orre on second guitar and drummer Mike Sjöstrand. Session bass guitar came courtesy of Mange Roos. Further line up ructions forced the departure of Johan Orre in January of 1999, being replaced by Daniel Sporrenstrand of XENOFANES repute. In April Hampus Klang enrolled on bass but with the exit of Sporrenstrand this latest recruit switched over to lead guitar.

HYPNOSIA covered POSSESSED's 'My Belief' on vinyl variants of their October 2000 album 'Extreme Hatred'. Digipack versions of the record included the entire 'Violent Intensity' album as a bonus. By November HYPNOSIA had solved their ongoing problems with a permanent bassist with the introduction of Lenny Blade.

In March of 2002 Castervall unveiled a Black-Death side project billed as FUNERAL in union with Chrille from SOIL OF THE UNDEAD. That same year Werdenskog featured as vocalist on SOIL OF THE UNDEAD's demo 'Seduced By Mental Desecrations'. HYPNOSIA performed a brief run of dates in the low countries but despite announcing plans for a new album provisionally entitled 'World Sacrifice' HYPNOSIA folded in June of 2002. Cab Castervall would turn up on tour in Europe in September of 2003 as live guitarist for infamous Grind act BIRDFLESH.

Former HYPNOSIA drummer Mikael Sjöstrand passed away on 8th January 2004 following a battle with skin cancer. He was just 27 years old.