Bells of Doom is a compilation released by the official fan club back in 2001! This release contains rare tracks from early recordings of the band. The first two tracks come from a rehearsal in 1987 when they were still called Blitzkrieg.
We have found a box with some of the CDs and now it’s available in our store. 
 
Blitzkrieg – "Rockn' Roll Jam"
Blitzkrieg – "Scared to Death (Excerpt)"
Therion – "Bells of Doom"
Therion – "Macabre Declension"
Therion – "Paroxysmal Holocaust"
Therion – "Outro"
Therion – "Ravaged"
Therion – "Black (demo)"
Therion – "Melez (demo)"
Therion – "Path of the Psychopath"