One big issue I have is where the ax blade is facing. I understand that you probably wanted to let us know it was an ax, but the way she's holding it makes it look like she hasn't swung just yet, like she's preparing to swing; however, the head position and direction of the blood splatter makes it look like the ax came from the left, went through his neck, and exited at the right. Is she getting ready for another swing? Perhaps. The way her body looks like she's either getting ready for another swing or is "relaxing" after a swing, though I feel like it looks more like she just took a swing. That's a bit of nitpicking on my part, but it is kind of glaring me in the face. Maybe not anyone else, I'm just saying a problem I seem to have.
The piece as a whole, however, is really nice. The bride's arms are a little disproportionate, but I can look past that because of the overall cartoony style of her design. The hair is a bit more realistic, which adds quite a daring contrast to the rest of her. And the groom is also a great contrast, with that amazing facial design. His hair is less realistic compared to the rest of him, which I also think is a great contrast.
So what can I say about this piece in as few words as possible: Daring contrast that really pays off.
The reason I didn't just do a critique was because I don't feel as tough I had enough information to write fairly and with enough strength.