@phoenix-yip I think the image is okay, but perhaps the issue is the foreground.
I feel like you should perhaps crop it so that it takes more of the canvas and really emphasizes the scale difference between the sword and the little person, all while keeping the sky in place.
Another tip I would suggest is creating a figure-ground by making keeping the sky bright but have the main focus of this piece a little darker with shadows to create a good contrast. Here's a final mockup.