Looks odd. Yet cool at the same time

You could use some clouds to increase the filling of dusk over the whole image, and you could use them to also add more shadows reflecting over the image (the ground) that way that sun/moon can get a more darkish tone, without really having to add more shading or making the shading more dense.
Mmh maybe you could have added a crow, skull, skeletal hand, wolf, or some sort of blade to the image to add a sense of ominous danger.

However i like it as it is, so just leave it like that, these are some well deserved 5 stars.