Prime's coloring isn't bad, just a tad bright--I know what you are thinking "Sean you always say that about Optimus." Just a thought, but what about the superimposed image of Sentinel Prime's head in the background because he wrought all of this chaos? Hmmm, maybe not. Perhaps as a separate image. I never realized how oddly proportioned Starscream's body is! He's got this huge torso and these skinny little legs, but I remember seeing that in the latest film when he's standing in front of the Lincoln Memorial, you've captured that design very well. I love how this is coming together, especially with the coloring. Even Megatron as a more limited palette has great detail and structure!
Thank you my friend. And nope :3 I wasn't thinking that at all, I was agreeing with you. Optimus will be darkened, (as you may see on the chest) but I'm working on it. I may add Sentinel in another picture against OP, but that's a maybe and in the future. Starscream was a PAIN IN THE AFT to draw and ink. I am going to do a picture of Megatron sitting in Lincoln's memorial.