Sarpsborg's THYABHORRENT, founded as ABHORRENT in 1989, released the demo 'Occultus Brujeria' in May 1990. In December that same year the group evolved into THYABHORRENT for the 7" single 'Death Rides At Dawn' for the Seraphic Decay label. Stian Johansen, a.k.a. 'Occultus' or 'Cultoculous' and editor of the underground fanzine Sepulchral Noise, would briefly perform with MAYHEM during 1991 following the death of singer Dead. Demos 'Incopnitus From Arcustus' and rehearsal set 'The Conclusion Phase' followed the same year.

Occultus subsequently forged PERDITION HEARSE for a 1993 demo 'Mala Fide', then Gothic outfit SHADOW DANCERS.