Well, it is a pretty occult idea here. Quite literally.
Satanists and other cultists. And that's before said protagonist is disillusioned and attempts to
leave the ranks of said Satanic cult.
Spoiler alert: Here thar be demons.
“…Judge not what a man has done, but judge what he could have done if he was a different bloke altogether. For art thou a leper? And a leper can changeth his spots…” --Rudy Wade, Misfits (Series 4, Episode 8)