In this video, Graeme (the audio technician for Ghost), along with a Nameless Ghoul discuss some equipment that the band uses. Graeme mentions as well that for the bass rack, a Pigtronix Disnortion is plugged in for "growl and attack", giving it the signature Ghost sound.
I quite like it but it's hard to see how it's THAT much better than other pedals I have
The Fuzz tones are nice. Having an Octava and Drive unit attached are very convenient but I tend to gravitate more toward my GT-500 for those sounds than trying to dial in something with the Pignortion OFO.