) but was famously accused of practicing "Black Mass" and "diabolical sorcery" by rival occultists like Stanislas de Guaita. Core Themes and Content

: PDF versions and related documents (such as prayers or ritual guides) are frequently shared on document-hosting platforms like Scribd. Anima Satanae-2 | PDF - Scribd

If you encountered this phrase in a specific context (e.g., a game, a song lyric, a forum post, a grimoire), please provide more details. I’d be happy to help identify the correct source or discuss related historical or literary references to the “soul of Satan” in Western esotericism.