Cant help with character design if you are specifically asking for that since we don't know much about the character you have. I just added more shadows and light based on the environment and added more green tint on the figure because of how green the environment. I don't know what you want particularly for the piece but if you want the character fit the environment, you can try a more lineless style but the lineart can also be a stylistic choice if that's what you prefer. Also, look up references to help with your rendering process.
i luv it thx

