Hmm if it's supposed to be nightmare moon there's some issues that makes it look like twilight. You should work with your fundamentals. For instance a dark valued object reflect less light you make it reflect too much use darker values in your lights here.



However the glow from horn don't look like a light source it is not the lightest part of the image the light reflecting from her skin seems to be about the same value.



It also look fake as her left side reflects a colour 0f light it cannot lights can only be reflected by. An object of similar color and nightmare moon is more of a dark blue than a purple or pink. The saturation of the purple light would be way lower. And the blue light would have more saturation.



usually if a warm light shines on a cool coloured surface it will eat away the saturation so it's closer to gray. This is essential to make an object look like the color you want correctly capturing the light on the object.



even if you say its your style i hope you at least don't want the coat look like twilights if it's not. For twilight that there is really good in your current lighting setting.