Having an Angel Comb itself be ‘hostile’ (in the form of a leviathan, enemy, or something else entirely) when infected I think could act as a nice (horrifying) progression of difficultly, and make the Bloom infection’s potential and affect even scarier while adding to the mystery. It doesn’t even nessarily need to be a real Angel Comb, maybe it’s a different lifeform that’s mimiced its appearence for some reason.
I don’t know where the story will go, and if this even makes sense on a biological level, however it seems interesting and I thought I’d throw it out there.