I'll start right off the bat with something a bunch of people dislike about "Black Butler": its inconsistent tone. In an instant, it will flit from dark, Latin-singing choirs and ominous dialogue to levity normally reserved for zany comedies. For me, the juxtaposition works, and it's a large part of what makes "Black Butler" so palatable. I find a world is more fleshed out and relatable if it doesn't take itself too seriously. Yes, Sebastian is a demon who ultimately wants to feast on Ciel's soul - but that's just how demons roll. It's FAR more engrossing to focus on the nuances of Sebastian and Ciel's simultaneous relationships as lord/master and prey/hunter, and how both relationships affect one another. Because the show chooses not to constantly dramatize the "demonic" elements, it can instead devote its attention to crafting a multi-dimensional world, characters, and relationships. We could spend hours on Ciel ruminating over his decision, but isn't it more fun to... not? We know that if he backed out (which he wouldn't, because he's fucking Ciel), the show would be over. It would be silly and boring to watch him debate his decision over and over set to dramatic music when we could be having fun solving mysteries and exploring the VERY unique world the show lets us sink our teeth into. Wouldn't you agree?
I have yet to read the manga, so I can't comment on when and where the anime deviates. I enjoyed the ending the anime gave us, but I look forward to seeing the ending the manga chooses. I love that this show has boosted A-1 Pictures financially so much, because "Book of Circus" is FAB as is "Book of Murder." And they're coming out with "Book of the Atlantic" in 2017 as well! Huzzah!
