Score: Very good
Ciel Phantomhive is a young lord, nicknamed the Queen’s Watchdog, charged with protecting England from the dubious and supernatural. He’s assisted in this by his servant Sebastian, who’s more capable than any human butler – he’s a demon.
Ciel himself isn’t demonic, but he is driven by revenge. The deal with Sebastian means that once that revenge is complete his soul will be forfeit, so he avoids making human connections. While tracking down those he has a grudge against, he busies himself serving the Queen by tracking down supernatural and other dubious things.
There’s a distinct note of horror in the cases Ciel and his butler face: animated dolls that used to be real people, a murderous cult, the ghosts of a pair of murdered princes, etc. He also takes on Jack the Ripper, and something very similar to the Hound of the Baskervilles.
Bad guys are often more fun, and there’s a distinct pleasure to be had from seeing Sebastian give a disproportionate beating to anybody foolish enough to get in the way of his duty.