Being high and mighty about never touching a drop just makes you a tool, or a mormon…or both.
A quick summarization of the scene as written by the commissioner: Demon - then back named Kayne - tries utilizing a memory restoration spell for circumstances explained in-story, only to have it go all horribly wrong, resulting in his mind and active conscious being completely locked away out of reach, resulting in what's left of it to become all feral close to animal like.