You need to improve on your colors, by providing working with in a color scheme, contextually monochromatic would be great here or blue, purple, and red. The textures on the character clashes heavily as it doesn't follow the folds... Like on the left arm area. Blood will be slightly reflective and fit the style of the rest of the illustration... Wouldn't the environment low lit like blue mostly dark blue, while the reds reflect heavily to create a contrast? The tongue is bleeding into the background... Please seriously work on your backgrounds heavily. As the color is way too abrupt. Try experimenting with the stylization here like using hard edge shadows, with soft highlights or the reverse. Here is a technique that would help heavily... Make a color layer, paint it white. It helps see if things are blending in or not.