Good work here Ayub. This is your best. Firstly I dont like the shadow render its too bgi and pixelated. You would be better off removing it and adding dark edges. Secondly the background is too desaturated for the render so to make the render blend more put light textures over him, and play with the render effects to make him match the background more. Maybe add some contrast as well.
kiu mate, this is your best no doubt! Despite the critisim I do like it, dont get me wrong