Kuroshitsuji's ending is a wild ride, and honestly, it depends on which arc we're talking about because the anime and manga diverge pretty hard. The original anime (not 'Book of Circus' or later seasons) went for an original ending where Ciel essentially betrays Sebastian after achieving his revenge, leading to this twisted power struggle. It's dark, poetic, and leaves you wondering who was really playing who all along. The manga, though? Still ongoing, with way more layers—like the whole 'real Ciel' twist and the Phantomhive family's deeper secrets. The anime's ending feels like a standalone tragedy, while the manga keeps unraveling new mysteries.
What I love about the anime's ending is how it sticks to its themes: futility, obsession, and the cost of vengeance. Sebastian’s obsession with Ciel’s soul and Ciel’s own descent into moral ambiguity make the finale haunting. It’s not a clean resolution, but that’s what makes it memorable. The later anime adaptations ('Book of Circus' onward) follow the manga more closely, so if you want closure, you’ll have to dive into the source material—or wait for Yana Toboso to finally wrap it up!