WIPs
I like it, it looks very interesting. But when I look at it I don't think dark 'gentleman' it looks more like dark character with just a metallic top hat. If you are still aiming for the 'gentleman' look it would be better to simply draw a gentleman and change a few things to make them look evil.
As far as background goes, I am not really a big fan of it. That's just my opinion but I feel like a contrast between the background and the person would be nice. I am not too sure on what at the moment but I will let you decide if you take that on board.
The current background is already suited with the character. You took the right choice to use a monochrome-ish thing for the background, it's because there are only black and white on the character (some red for the blood effect doesn't count[still dark]).