Hey! Welcome to the community!
You'll have to forgive some of the comments, critiquing things is oddly difficult here, given everyone's individual styles.
If it's alright, I'd love to give a couple pointers!
SO, when creating a wallpaper, you'll wanna be careful about using too much bloom, especially for things like words. It'll end up filling up your scene too much and people can lost interest quickly.
Instead, see about playing around with spotlights and pointlights. Since it's only an image, and not an animation, you can get away with more complicated lights and using spotlights to your advantage. Just be careful about washing your colors out with them. We still wanna see what you got without it all being red.
Dynamic poses and spacing are also great for posters. You dont wanna fall into the whole MCU movie poster hole (which is really easy, trust me).
For posing, full extensions, minor stretching, and bends are your friends. You've got the bends down, but lets see about where the limits are with a character's realism and explore that!
If you're up for giving it another shot, I'm all for staying updated! Can't wait to see what else you've got.