Returning the favor.... of your kind critique for my work.
I am not familar with the story if that is important to what is being shown...
The front lead character is very well done. The tallest character, and the two on the right, in the back is not done up to that same high standard though. Jpeg compression has something to do with it, but adding some extra directional lighting, especially on the dark skin, would better show the physique details. An option, to see how it works, would also have the tallest character having his head turned more toward the viewer. Like the heavy character's head being opposite that of the cloud... and I like how the head in the clouds turned out.
Nit picking of course. It's evident that you know what you wish to portray.