I have listened to some bands that blow that away in terms of straight up disturbing satanic lyrics..... Mercyful Fate, Slayer, Deicide, Cannibal Corpse (more gore than satanism), Gore Rotted (same deal as corpse).
Try Dark Funeral, old stuff of Bathory's, Emperor, Dark Throne and Impaled Nazarene for blatant Satanism.
As for AC/DC, I always heard (when I was younger) that Highway to Heaven was the anti-thesis of Stairway to Heaven when back masked. That's an interesting story about The # of the Beast Ryan. Wish there was a story like that about Hallowed be Thy Name though. Would make it all the more mysterious!