The possessed man (e.g., Regan in The Exorcist , Merrin’s patient in The Exorcist III , or countless demoniacs in folklore) is a different tool. Here, the devil has not visited from outside but has colonized a human self. His utility is unmatched for:

According to detailed player guides, the main story concludes when you forge a pact with the ultimate nightmare, known simply as . This is the final story flag. To reach the "true" ending, players must achieve a state of perfect corruption: performing vaginal ejaculation (and forcing orgasm) on every single girl in the game. Only then is the contract with LILITH —the highest-ranking devil—unlocked, leading to the game's final, horrifying revelation about the demon's true purpose. The nature of this purpose is deliberately left vague here to avoid spoilers, but it's a conclusion that gives the entire experience a disturbing new context.

Over the next few days, Elijah began to experience strange occurrences. He would find himself in places he didn't remember going to, with no recollection of how he got there. He would hear voices in his head, tempting him, goading him, and laughing at him. And then, there were the nightmares.