I don't really know what to think about this, so let's start with the simple stuff. You can tell that a lot of care into the art, and the character designs are interesting. Tonally, it swings between horror and light-hearted banter. It's not all extreme kink from start to finish; there is actual character development and world-building occurring.  Certainly check it out if you're looking for unusual BL and can stomach extreme kinks.

However, I feel like the story that was set up in chapter 1 didn't really follow through for the rest of the volume. And since I was more interested in the themes of chapter 1, it was a disappointment to see those themes get set aside for new ones. Specifically, the first chapter sees our human character grappling with the knowledge that his sexual preferences are abnormal and extreme and feels tortured by this. He doesn't want to hurt anyone, but his desires aren't compatible with that. Interesting stuff, in my opinion, and it's a very emotional chapter. But then he gets taken to hell, and all that stuff previously set up becomes a moot point because now all the kinks he wants ARE possible. His internal conflict is replaced by an external conflict of trying to survive his new situation and grow as a demon, which is interesting too but not what I came for.

I'll give it another volume, I suppose. See my content warning for more detail on the kink aspects of this. I'll note that while the content is heavily present, I personally did not find it disturbing because the art was more delicate than detailed but a friend who read it thought it was disgusting. Your mileage may vary, I guess,