Note - review for manga as far as it is 
 This story started off with a very light, comedic mood, with darker undertones. Later on, the story evolves into a more darker mood, with occasional funny moments, which caught me by surprise. I should've expected it, since it is a story of revenge, but I honestly never expected it to become so deep and serious. 
 I rate stories based on whether they're a light, funny story, or if they're more serious and deeper - light funny stories may get a higher rating, but I wouldn't care much about them, and they do have different standards from more serious stories. I'll probably ignore more things and just enjoy it as a story. So Black Butler caught me by surprise in that aspect. If I'd known to expect a more serious story, I would've seen the beginning in a different light. 
 What revenge, btw? I hope the arcs tie in, somehow to Ciel's revenge (if the Joker arc was his revenge, it didn't come off that way...) or I'll be seriously disappointed. 
 It says that this story is Victorian, but the later arcs have some very unVictorian things. And they do seem kinda random... If you ignore that, the arcs themselves are quite interesting. However, since this is a manga in progress, I'll give it a benefit of doubt and wait until it finishes to come to a decision. 
 I'm not sure about the main character. He did have a sad and painful past, but he did end up surprising me, around the time when the story shifted its moods. He is quite intelligent, but without his butler he's very helpless. Part of how he achieves almost everything is because of his butler. It's like he's so dependent on him, he'd be a totally different character without his butler.