I TOLD YOU TO STAY HOME D8

The lineart is a bit of a failure. It was one of those pictures where I concentrated too much on the little details too soon and not enough on the overall picture.
My first idea was to have Optimus blocking Megatron's sword but I couldn't do that without:

1. Blocking his chest and part of his head.
2. Blocking a HUGE amount of the background. Although it doesn't look like it, I put a LOT of effort in it. :c

Okay, so since THAT was out I was stuck with this conundrum: how am I going to make it look like they're in the middle of a battlefield with Sari popping up behind a rock going "HI OPTIMUS! ;D" and Optimus going "ad;lfja;rjgekegyu?"
So I figured; okay, we need more rubble.... AND SMOKE.
I hope I got the point across. I REALLY DO.

His right arm and hand were MAJOR BITCHES. I still hate his arm.

I'm not going to touch this picture until I learn to make clear, clean lines, so if anybody has any suggestions/tips/hints please help me out. D;
My linearts are always sketchy and rough and for once I want this picture to end up looking really nice.