As a whole, let me say, this is amazing! This is the sort of work I strive towards and I love the work. The whole image tells a story and is well put together.
I'm most amazed with the chain link and stance of the knight. His head is awkward. Like held uncomfortably between hanging down and the connection to the spine feels a little lost. Maybe it's the angle on the face? I'm not quite sure. But don't beat yourself up about it, faces are hard. The armor sits perfectly like I could imagine seeing it and it's fairly realistic.
The girl in the background blends with the rays of light which is amazing. The whole scene.
You did an incredible job with the details and not having the details pop out too much. They settle into the piece right where they should be.
I would say that I would focus on faces and how the movement and expressions change the faces/shading. Not that they're bad, but out of all the incredible work here they are the only thing holding you back from that next level in my opinion. As well this is based on looking at this piece only, so take it as a grain of sand.
It's such a realistic picture! I think first of all you're amazing for having done this by hand with pencil mostly without the whole page turning into a smudge-fest. I love the work you did on the moon.
I guess my only critique is IF you were trying to make it look like a hill just on the other side of the road that's very close, then you did great, but I suspect you were going more for a mountain in the distance, while showing some of the details? If so the only thing I can think to do differently is less contrast between the dark and bright colours on the left side of the mountain. Because of the 'focus' so-to-say, it makes it look like a ridge nearby. The mountain/ridge/hill seems a little disconnected from the left side of the tree to the right.
No stars? It's a cloudless night? Not sure how you would do that in charcoal/pencils.
Regardless of my critique, overall is amazing work and I could see this in a book easily!