The line work is nice and clean, but right off the bat, the color and color rendering technique is severely lacking. The overlapping lines of dried marker are highly distracting and looks rushed. I suggest prisma colors if you aren't already using them(there are several tutorials out there), or if you're a bit strapped for cash, inks or watercolors are great for building up color. Or if you have scanner, you could digitally color it. The choice of blue confuses me, as it appears nowhere else in your image, so maybe try black? It would make the eye man more intimidating. Also, when shading, try not to just press harder with whatever medium you are using (it seems like you're doing that), try using the opposite color, or a color that's similar but higher in value.

The composition is very centralized, which is fine, but the uneven curtains, and cloak are nixing the whole thing, and making it off-balanced.

In terms of anatomy, the main offending issues that I see are that the woman's eyes are ridiculously far apart, they should be more central;the top of her neck is too thin, it should move out a bit more; and her feet are too big and her hand a bit too small. There's also something a bit wonky with her legs. I would suggest finding or shooting a reference of that pose, and as you draw her, imaging how she would look if she was getting up.

As for the subject matter, I personally feel that crossovers tend to be fairly ridiculous. But that's just me. ;D

Cheers!