Hey!
Nice painting. Really stylized, but very interestingly so.
There isn't much feedback to give, considering that this is mostly designed and is mostly intentional. Though, there are a few things.
I think the high contrast works designwise, considering the black background which fits in the dramatic poster look. The problem is when youre going for a stylized, almost cel-shaded figure. There is a mixture of both cel shading and form shading, which kind of works, but you usually don't want to mix things unless they work with each other.
This leads me to the face, which is a result of the mixture. Her left side, is flat and drags a lot of attention to it, which is good and bad. It feels like it is popping out of the helmet, which isn't what is happening. Her right side, does feel encased. However, it is very difficult to drag my eyes out of the sharp left side of her face due to the intense colour.
Which brings me to the last point; colours. I think you did nicely, you have a strong, bloody red and a very cold and mystical cyan. They both play well into the eerie, horror theme.
Good job though!