mike's brutal voice

Most of it is natural, but as in Demon of the Fall, when he had a cold it came off alot more evil, plus it sounds like they layered the growls too in some parts. The Master's Apprentice and BTPISIO parts sound very obviously like effects to me however.
 
They just use another layer of them growled at a different pitch at the end of Master's Apprentices, and in a lot of places on BWP (most obvious is the part after the interlude in the title track). I think he whispers under them in the first part of Demon Of The Fall to get that effect.

They're more just production techniques, than actual vocal effects. I don't think I've heard any bands that cheat the growls though, so I don't know what that even sounds like. Who does?
 
DEICIDE cheats the growls. glen benton is actually a 12 year old girl. i think she got grounded once, couldnt come into the studio much, and that's why 'in torment in hell' sucks so much.