Just critiquing this really quick.
The biggest problem I have is your shadows. They're covering up too much and wouldn't extend onto the side of the bridge like that. In fact, you can see that the bridge and characters both have light coming from the front but your shadows are projected into the light source.
There isn't much to say about the editing done. There isn't much done is why. Kahn's head does look good like that but his mask looks like it is missing the front piece (the part that looks like a skull).
The blood effects are flat in appearance. Add more depth and color to your edited blood.
Jade looks silly like that. It pulls away from the image. Also, the height you have Kahn, he would undoubtedly have to be jumping to get hit in the stomach. A better idea might have been to have him throwing an inanimate object that was knocking Kahn's helmet off (his hammer a la MKSM?).
Decent execution on a mediocre (imo) idea. Nothing spectacular about it so overall it's just average.