This is an awesome piece. You're really good at digital painting - you paint smoothly. Its interesting how the red theme picks up around the piece, like a blood red storm brewing. I really like Enjolras's grim expression and the detil you put into their hair. However, I feel that too much of the clothing blends into the background - I think they need more outlines to prevent that. It also looks strangely inconsistent when you look at the faces with the outlines and the bodies without them. The badge thingies (I don't know what they're called) could also use a bit of definition because they blend into the clothes a bit too much. It would also help define them from the background a bit. I think the flag could do with a bit of outline too.
I hope you found this useful and I haven't trod on your toes.